OK, this is a fairly standard gag. You take a familiar phrase, illustrate it literally instead of figuratively, and you’re good. Except that eggs are terrible to draw.
Seriously, try drawing one now. It’s not a circle, it’s not an oval, it’s this sort of oblong teardrop but not quite.
You know when it’s right, but it might take you 2 or 3 or 12 times to get that line to curve juuuuust right.
I guess that’s what you get when the gag comes easy.