There are no rules.
Think outside and inside and on top of and underneath the box.
Ignore the box.
If you encourage viewers to see something they haven’t noticed before, or to think differently, or anger them, or give them a reassuring warm feeling, or present an image that haunts … or any reaction at all, then you’ve succeeded to some degree at least.
Viewers have responsibilities as well.
I like the thinkers who are interested enough to see beyond face value. Yawning is very annoying.
Art can be a problem to be solved and sometimes it isn’t.
If you need me I’ll be in the shed.