It goes without saying that the inside must be absolutely smooth.
My thinking is that this little thing might be handy to have in a kitchen drawer.
If you can crack an egg with one hand, you can hold it in the other hand.
Or it could sit over a glass, measuring cup, inside a small bowl.
The dome design would work well as a lid for an incense jar or a garlic keeper too. Here it is sitting on a small flared bowl. I think lips and flanges are in order for a jar or keeper, though.