It's not really a secret at this point that Apple has been finding some unexpected results in iMessage's GIF search. Most of those have been pornographic — first there was an explicit My Little Pony GIF, then there was hardcore porn, and then there was a bunch of other nudity that Gizmodo found.
It turns out there's also a Nazi meme and various GIFs of Hitler.
If you search for the word "power" in iMessage right now, the first result will be a meme'd image of the Power Rangers giving a salute, with a swastika in the background and the words "Heil Hitler" flashing over them. It's a blatantly offensive GIF, and the fact that — like some of the porn results that popped up — it came from searching a completely unrelated term makes the problem that much bigger.
iMessage's GIF search will also pull up various GIFs of Hitler if you search for "Nazi" and "Hitler." Meanwhile, a search for "Jew" results in a South Park GIF of Cartman saying "You stupid Jew." The GIF search then turns into a straight image search if you look for terms like "Holocaust." There's an argument to be made that a built-in image search is helpful, but it doesn't look good when it's sold as a fun feature for sending silly images to friends.
Apple has yet to comment on the issue, but it seems to be removing inappropriate search terms and results as they come up.