Don't all the male ones do that pose and all the females do the other one?
Malva is a boss. I wish we knew more about her motivation and her backstory, and I also think that it is really interesting that one of the strongest trainers is "evil". Normally GF is all like "Strong people are good and evil ones are weak" but Malva, being a part of an evil organization, is still a serious trainer and part of the E4. Also, does the rest of the E4 and Diantha not know or do they just not care? I feel like there would be background checks before you get into one of the biggest organizations in the Pokemon world.