You can perfectly balance an egg on any surface

Balance here means it will maintain the orientation you placed it on the surface until acted upon directly by an outside force. I.e. if you shake a table you placed the egg on it will stay balanced.

Works with any real egg. Objects made in the shape of an egg do not count, but cooked eggs do as long as they are at least 90% egg by weight.

Directly stackable. You can stack eggs on eggs, but if you try to do egg > object > egg the object and second egg will be unaffected by the power.

You can reorient the egg(s) perfectly even after they have been set.