Concept idea for Google Hangouts share button (need help from photoshoppers and/or animators)
The camera icon on the lower right is replaced by an attachment icon, just like the one in Gmail. Touching this attachment icon triggers a white bar to slide from the left which only covers that lower area where the rectangle of the text box is. On this white bar are three grey icons divided by grey lines for a very minimal look. So, up to this point the chat window remain undisturbed, no pop up messages yet. The three grey icons are camera, location (the icon is just the familiar Google Maps pin in grey) and Contacts (The peoples app icon works). Hangouts Already does a nice job of giving you ability to annotate a photo before you send. However, I think it can use some improvements. The shared photo sits in the center with a little "V" top on the bottom, pointing at the "now-reappeared" text box for annotation. (currently, the photo is more to the right, looks out of place and confusing if used for the first time because the photo looks kinda like it's already posted in the chat timeline). The same thing if a location is shared. It brings a simple snap from Maps with the "V" tip for commenting on the location you're about to share. Contact sharing should prompt you to check boxes of details you wish to include/exclude from a contact profile before you send it (this is already possible in Android, but Hangouts does not support it).
I'm sorry I couldn't provide any illustrations. I'm just bad in drawing/editing/making animated videos or gifs. I hope some talents here got the idea from what I typed and find the time to throw something together and share it with us.