Looks like a ministry of funny walks convention

Honestly given how consistent the rest of the image is on all of the things which would not be moving, minor errors with people walking on the street almost more looks like phone camera processing/stitching errors. Especially with how many phone cameras now take a burst of photos and stitch them together to make a higher quality photo

There is nothing wrong with the people on the sidewalk. Only one has a bit of a weird turn, but nothing that can't be explained by movement.

No, it is most likely a real picture, but with only the trailer added through AI. Everything else seems to be correct, but the lettering and number plates are off.