I've come across a Twitter post saying you can see Megumi's nipple under the water and I think you really can.

Kurmy said in comment #2627586:

I've come across a Twitter post saying you can see Megumi's nipple under the water and I think you really can.

I think I see it too, but at the same time, I find it hard to believe they would let something like that slip into artwork for a generally SFW gacha game.