those tools are not very trustworthy. but i agree that upscaling is likely.

One of the kids is missing a head, one child has two left hands, some children don't have legs. The Darth Vader mask and shirt don't make sense visually, and you can see the same shirt repeated on the child with no head.

The desks and chairs are inconsistent, looks like there are a few different styles but they also have bits that don't connect to anything. I don't know what it was like in the late 70s but generally classroom furniture is very consistent.

Then there's something really strange going on with the shadows, like the smurf and clown have dark cutouts attached to them that could be shadow but aren't.

I can't figure out what is happening with the Disney princess mask, it looks just pasted in

first, look at how homogeneous it is. all the costumes consist of a mask and a shirt. every desk has an empty paper on it. everyone is looking at the camera. almost every costume appears twice. this is an all-black classroom in the early-to-mid-80's, where someone is standing at the front of the classroom with their back to the windows (no light from any wall), taking a photo with flash of kids just sitting at their (all left-handed) desks in full costume.

second, think of the context. bluntly, this photograph should not exist in a world of film cameras, because even without all the visual oddities this is the sort of thing you'd do a photoshoot for. you'd ask all the kids to line up against a wall so you could get all their wonderful costumes. this is a spur-of-the-moment shot, like you'd do with a phone today, and unless you're the teacher you wouldn't be in the spot the photo is taken from.

Edit: more interesting details:

• count the table legs. they're all different.
• also the tables are completely misaligned. like they've been placed for the photo.
• why would a smurf costume include a picture of a smurf?
• one of the evil knievel costumes has "dukes of hazzard" sewn on.
• that one kid without a mask looks like he's melting.
• back to the smurf costume, what are those pants?
• why is there a piece of cheese on one of the tables?
• the darth vader costume includes a shirt with orange fur and a picture of darth vader on it? and the kid who has presumably left for the bathroom behind the front clown left their shirt?
• *points to darth vader mask* "what's wrong with your faAaAaAace?!"