Some of the stars are round and quite a few are egg shaped but then it is cropped so even small tracking errors will show up.
It is true some binaries unresolved can look like egg shaped stars but then there are too many for that.
I think it is a very minor point and does not detract from the image.
Perfect round stars may be ideal but can be overemphasised as a necessity (says he who rarely has perfectly round stars
)
Greg.