How to make kids rotating art frame work?

I have a question for y’all - consider me a noob here.

We have toddlers who bring home artwork. Popular Instagram reels/TikTok advertisements have included box frames where you can hold kids art and switch it out easily. So we got a few.

It’s got two elastic bands to hold excess kids art agains the back, and then a matte and glass in the front. The opening of the Matte is something like 11 x 14 (kids art is often on 8.5x11).

So the problem is essentially that the elastic band strategy would work great if the back were the front. There’s nothing to hold the artwork against the front glass, so the artwork just falls down inside. Any tape we might use is incredibly obvious and visible. I thought about buying backing board, (tape the artwork to the backing board and have it held to the glass by those bendy pins that hold the glass and matte in the front kind of idea), but it’s pretty expensive. My wife has suggested maybe we add another elastic band behind the glass.

Probably not a big deal, but we’re dealing with future Rembrandt and Manet here.

Can you think of any ways to make this work well for us? Any ideas are appreciated, no matter how ridiculous 😉