Last week, Twitter introduced an update billed as an effort to make its central timeline more visual. Image previews on the web and mobile versions of Twitter now appear inline, creating a visual feed that sometimes looks more like Instagram than the Twitter of old. "So many of the great moments you share on Twitter are made even better with photos or with videos from Vine," wrote Michael Sippey, the company’s head of product.

But it’s clear that all those images are merely bait for what Twitter is really going after: the social-network fuel known generically as "engagement." Likes, hearts, comments, favorites, retweets — whatever form engagement takes, the result is a rush of dopamine straight to the user’s head. It’s the magic that makes people return to places like Facebook, Instagram, and Tumblr multiple times throughout the day. Each of those networks persuaded its users that it was a place that they would be showered with validation. And with that validation came new users by the tens of millions.

With validation comes new users

Twitter, meanwhile, has offered the average user a shower of text and links. Feedback, in the form of replies, favorites, and retweets, has been harder to come by.

Now, just days ahead of an expected initial public offering, Twitter has taken its biggest steps to date to make the service more interactive. Just as important as the sudden flood of images into the stream is the fact that the main interaction buttons — reply, retweet, favorite — now sit below every tweet. Where in the past tweets hid the possibility of interaction in a drop-down menu, today every tweet offers an encouragement to engage, right in the main feed.

Twitter declined to discuss the changes beyond what it said in its blog post. But internally, the alterations to the timeline were viewed as some of the most significant in two years. That’s when the company launched the so-called #newnewtwitter, a near-total redesign that introduced the Connect and Discover tabs. Connect marked one of the company’s first serious efforts to boost engagement by giving users a standalone feed of all the ways in which other users interact with them.

Days can pass without evidence your tweets are being heard

And yet giving users a feed of interactions seemingly did little to increase them. A person with thousands of followers may see replies and retweets daily. But to someone with 50 followers, or 100, days can pass without any evidence that their tweets are being heard. Some users derided the company’s recent introduction of notifications such as "someone favorited your retweet," but they speak to how hard Twitter is working to persuade users that their contributions aren’t going unnoticed.

Meanwhile, it’s hard to post something on Facebook or Instagram and not receive some sort of validation, whether through a like, a comment, or a share. With Facebook, that reflects the kinds of connections that people have on the service: for the most part, they are friends and family members who know you in real life, and are therefore more likely to respond than the strangers who often follow a person on Twitter.

But Facebook has also excelled at creating a highly interactive stream, sorting posts in the news feed according to their predicted popularity and lowering the bar for "liking" something to practically nil. (It is all but impossible to imagine Facebook ever having considered putting its all-important like button in a drop-down menu.) Social networks are often about projecting the best possible version of yourself to an audience of friends and strangers, and no one wants to perform to an empty room.

People complain they just don't 'get' Twitter

Of course, none of that stopped Twitter from amassing more than 232 million monthly active users. Twitter’s value for distributing news and information in real time is unparalleled among its peers. And yet for every person who is delighted by the whizzing stream of text that has formed Twitter’s backbone since its founding, many more are turned off by its eccentricities. Even in tech-savvy San Francisco, it’s common to hear people complain that they just don’t get Twitter, have no idea what to tweet, or used the service for a while and quit.

Meanwhile, Facebook reported last week that it now has 1.19 billion monthly active users, powered by a highly curated news feed that rejects strict chronology in favor of the content most likely to delight. The average user spends more than eight hours a month browsing Facebook. And while Facebook performs a different function in most users’ lives than Twitter does, ultimately it competes for the same time, attention, and advertising dollars.

The data says people like pictures

Little wonder, then, that Twitter has begun to incorporate some of the elements that have helped make image-heavy communities like Facebook, Instagram, Tumblr, and Pinterest so effortlessly interactive. The data has spoken, and the data says people like pictures.

Which isn’t to say the changes are going to be popular, particular with Twitter diehards who have come to rely on that fast-moving feed so dense with news and information. Some critics worry that Twitter has sacrificed its original vision in the single-minded pursuit of growth; others have complained that the image-heavy feed is a move intended more to please advertisers than it is to improve the user experience.

But for those who crave the Twitter of old, the company has an alternative in place: Tweetdeck, the business-minded Twitter client that it acquired in 2011 and continues to develop. If it’s an information-dense stream of text that you crave, that’s where you’ll find it. (Sadly you won’t find it on mobile, though, as Twitter killed off Tweetdeck for iPhone and Android earlier this year.) The main Twitter app has other plans, though, and it’s putting them into action.

The question is whether this redesign can bring Twitter its next 200 million users. The company has rarely taken so big a gamble with its core feed, and it won’t be long until we know whether average people are embracing it. With Twitter going public before turning a profit, the pressure to broaden its audience is only increasing. Pictures, videos, and buttons may not prove to be the winning approach. But given what’s at stake — the quest to become a service that offers something to everyone — it should come as little surprise that Twitter is trying it.