Reimu and Youmu's breasts are both supposed to be 95 cm according to this. Yet Youmu's breasts are visibly way bigger than Reimu's here. I think the artist just messed up on Reimus proportions.
crossing arms under large breasts can make them appear bigger, as it moves the mass up, closer together, and even push them out a bit. so they are the same size, one just has a different shape.
Reimu and Youmu's breasts are both supposed to be 95 cm according to this. Yet Youmu's breasts are visibly way bigger than Reimu's here. I think the artist just messed up on Reimus proportions.
They look about the same and Youmu has her arms folded under her breasts which would make them look more full.