The only thing I'd dispute with the comment above is:
The embryo in a reptile egg sits on the underneath the top surface of the egg. Hence, it is wrong to say that flipping the egg with detach the embryo (which will then be at the bottom)
Most people say that flipping it causes the embryo to sit at the bottom and then is "drowned" in its yolk. Is there any evidence of this?
And if the drowning is true, then there must be a maximum degree of rotation before it drowns. picture this, embryo is on top, u turn the egg 10 degree, it's still relatively top. U turn it 90 degree, the egg is on a side wall.. will it drown? a full 180 degrees and its definitely in the bottom.
Firstly, I dont really believe the drowning theory. Its unproven and to simplistic. Surely evolution has accounted for snake eggs to be subject to some movement. Imagine is a female's nest is attacked by predators. In her defense of the eggs, moving her body and distending the coil, at least one eggs would wobble.
ps. Its healthy that we are discussing this. Too many care tips have no scientific basis. I hope someone with the means picks up on this and tries to prove the theory, one way or the other.