Those "show the female form" a big no-no in for Islam.
Those burkinis show the female form as well...
The basic requirements are that when in the presence of someone of the opposite sex (other than a close family member - mahram), a woman should cover her body, and walk and dress in a way which does not draw sexual attention to her. Some scholars go so far as to specify exactly which areas of the body must be covered. In many cases, this is everything save the face and hands but others require everything save the eyes to be covered.