YouTube Testing GIF Sharing Option
YouTube is testing a GIF sharing option; apart from Share (for a URL), Embed (for HTML code) and Email (take a guess).
YouTube hasn't officially announced the new feature, but it seems to be testing it on select channels. Click on any video from Good Mythical Morning or The Idea Channel (the only two channels we found with the feature activated), for instance, and you'll be given the opportunity to make a captioned.
YouTube starts the GIF at the point of the video that was playing when you click "share" and allows it to be adjusted via timestamp or visual slider.