Hey Maggie,
I definitely agree with your point on the Egyptians focusing in on the afterlife and easing that transition. You state that the practice of high burial status was also practiced in Mesopotamia – but (if I recall correctly) that was also the extent of the Egyptian’s practices as well, at least up until the New Kingdom where there are some lower class citizens that are buried (such as scribes). I think there religious traditions were most definitely different, while the burials were somewhat similar. Egyptian art as a whole just had much more of a focus on death itself.