That's clever. clear to see underneath. I don't know where to get,but that's smart.

My custom cabinet maker built similar units above my fridge - but built them as drawers instead of pullouts (which are much easier to use).

I use to sell custom pullouts. I think this is a regular wood pullout where someone router out a hole in bottom & put in clear, thick acrylic & or tempered glass insert.

Kind of like making a glass cabinet door & inserting that as bottom of pullout.

I would be nevous with glass above my head looking up & placing things in. If it can break, I'll probably be the one to do it by accident.

The only concern about glass would be breaking, but it would not scratch as bad as acrylic. I think I would use acrylic & make it so, it can be replaced easily if need be.

Like the concept.

You might want to check with a place like Drawer Depot. I've ordered drawers from them. They have specialty drawers in the shape that you show above. Perhaps they can customize them. Doesn't hurt to inquire. I'm including a link (I'm not affiliated with them). Drawer Depot specialty drawers

There are online places that sell drawer boxes made to your custom sizes; I would bet that they could do this for you without a lot of trouble. And if you were wiling to have a straight, angled end instead of the curving one, it might be less expensive (bcs they can cut it straight on a table saw instead of needing a jigsaw and a pattern).
https://www.barkerdoor.com/Baltic-Plywood-Dovetail-Drawer-Boxes-p/drawerbox-baltic-dovetail.htm