WT…what is that for on top of an egg incubator?

On top of the egg incubator cover, there is a small dished pocket with a LED light in the bottom.

64 eggs automatic incubator
the egg scaner on the egg incubator

That thing is a device to check the eggs’ incubation. Just put the egg upon the dished pocket, turn on the LED light, and you can see the embryo develoment status perspectively.

incubator functions intr
checking embryo by the egg scaner on the incubator perspectively

Yeah, a little bit like money scanner. But only for eggs, not for money.