I was scrolling on YouTube and saw a new beta feature appear. I checked with another creator, but he also hadn’t seen this before. I am part of the beta feature testing program, so I sometimes see new features show up (and I let you know what YouTube is testing). These features are tested sporadically, and sometimes they only appear on individual videos. This feature was so new that I can’t find it anymore, not even on this video. I’m also not sure what exactly you want to test for. It was synced with the video, like a live broadcast.