When our kids brought home stuff about which I had NO clue, I’d just say, in a delighted voice, “Oh how interesting. Tell me about it!”. Then they’d explain what it was supposed to be, at which point I’d just nod my head and say, “Wow that’s really neat!”. They were always pleased to describe their ideas and the process of bringing them to artistic life. ;o)
Good response and variations of it should also work with confusing adults!