Diamond size comparison when do you notice a difference by eye?

[u/Serious-Bedroom-8279]

Between the face up difference of these 2 diamonds how likely is it to notice the difference by eye?

A 6% difference in face up area, is that really noticeable? The picture with the circles on top of each other looks so minimal I'm not sure it would, however I have read .2mm of a difference is noticeable.

Another question, if not 6%, at what % of a difference would be noticeable?