I would just presume that the bikini bottoms have really baggy crotches and wouldn't buy them.
The market for bikini bottoms for transwomen is too small, so is this actually aimed at women?
I would have preferred if they showed Gigi etc in a nice pair of board shorts so they would become trendy and I wouldn't have to trim the ol lawn before going swimming.
Speedoes are specifically created to contain men's cock n balls. If they try to swim in a pair of women's bottoms there will be no way to stop it all flying out.