What details help the viewer know this is a form and not a shape

They used their senses of sight. When they looked at the item they looked close.

Explanation:

I do not a picture or anything but the answer I put came from a feeling, I think that could be the answer but if you do not agree just report my answer.

personally, i think the games do because it's actually them controlling it. this might cause them to think it's okay to do it for real. as for animated movies i think they are mostly fine because they're animated. also, animation has come a long way causing animated movies to become more real but 30 years ago this wouldn't be as big of a problem as today.