Unless this is her "relax and hill out in warm weather" outfit, it's nonsensical. And it doesn't look to be that since it seems to have some actual armoured bits. Why would anyone wear armoured pieces but expose their most vulnerable target?
Have you ever worked out? It's fine to show off the stomach if the character is fighting in a warm climate.
You don't need a sarcasm tag, because it's actually a valid argument.