Hey, don't know if someone already told you yet but the Quetzalli (male) extra's don't unlock when you buy the gender switch potion in 0.7b. I scoured through the entire forum and the game only to find that it's meant to unlock with the potion extras but it never happened so I'm assuming it's a bug.
Great game though! I love Nii, she's the best.
There is no gender swap picture for male quetzalli since the player starts as male and when I decided to put the gender swap I added the female artwork. I can check in the future if add it but probably not, since it wouldnt make much sense besides being a bonus artwork. There will be some exclusive art for quetzalli being female and other male depending on the context.