A few descriptions from LSM include that broken cars were seen in the clip, or that bodies landed on cars. Shortly before the old subreddit was closed, someone posted a clip showing cows falling from the sky next to the Twin Towers and hitting cars and the ground. I'm not exactly sure what the video was about, but I think it was some kind of commercial. The video itself was very low quality, so if you only watched it briefly, you might think it was people falling from the sky and not cows. The video led many to assume that this particular video caused a Mandela Effect, or that this video was included in various 9/11 jumper compilations.

I just searched for the video, but I can't find it right away. I'm sure someone here knows what I'm talking about and might post it.