If this was a gif then nobody noticing would be a good argument but it's a still and only their legs are showing plus if the pizza was cut correctly so the slices could just be pulled up then that position is plausible. It could still be ai but those examples don't fit so well with a still of only half of the people and what would happen with a properly cut pizza. Are there any specific things that are more subtle that jump out as an example. I'm no expert at ai but I did find this on Pinterest and they mark images that are ai altered ones and this wasn't but I can double check.
