Google Image Search's mobile interface tests a new feature that starts playing snippets from a YouTube video at the top of the search results page. It's not disclosed as an ad, there's no sound and you can't stop or hide the video, which continues to play on repeat.
Right now, the experiment seems to be limited to fashion-related queries like [men jackets], [lookbook], [winter outfit], which match videos from YouTube channels like New Look and River Island. "New Look is a South African-owned British global fashion retailer with a chain of high street shops. (...) The chain sells womenswear, menswear, and clothing for teens," according to Wikipedia.
Google only shows labels like: "New Look on YouTube", even though this looks like an experimental ad format. I hope it will never become a regular feature, as it's pretty annoying and it wastes Internet bandwidth.