Mmmh, not sure i like that handling with the 10%. I wanted it rather reliable, making looks more dependant on the image packs not randomness.
The image packs i downloaded all have a very redundant handling of profile and formal/swim/ecchi already and the majority of formal pictures had dresses (especially now that escort is a different imagetype).
I included the variety in a subcheck, but i wanted the default always be formal (or swim, lingerie, nude respectively). Such things as special items or traits should be handled there. I could explain it better with paper, sorry

Basically, if I equip a swimsuit, i want one of the swim pics to appear (or one profile pic with a swimsuit ideally). Not a dress, not lingerie, not casual profile, not nude. If the change i make as a player only works 10% at a time, it seems pointless to include. If a girl has 1 swim pic and 50 profile pics and she is wearing no swimsuit in the 50 pics, i still want to see that 1 swim pic all of the time (though i would either unequip the swimsuit or add more swimpics if that pic starts to annoy me or give her more dress items and have her wear something different each day).
Maybe it is better to use new categories like profilearmor, profiledress, profileswim, profilelingerie and profilenude for this feature as default and the existing ones like swim, maid, dom, formal etc. only depending on special conditions or traits.
That way anyone who wants to control appearance can edit the packs and it will not get puzzling results for the others.
Also, if you treat profile as a mix of clothed pics, i miss the nude option. Makes sense for free women, but for slaves she not always has the choice what to wear. If you want to keep the default "no items=clothed", maybe check for "isslave" and "nude" (similar you could check for exhibitionist trait and THEN make it random if the profile is nude, ecchi or swim. For slaves you could make it dependant on player disposition) and make that the nude profile option.
But bugwise i tested it a bit with equipping a swimsuit and the boolean declaration definitely works as you intended (after checking back and forth for a while ingame with a char that had no swim pics in profile pics the correct category appeared).
Thanks for including it in any case, but i think due to the randomness people will hardly notice it or report it as a bug. And sorry for the wall of text, it ended up more as more (annoying?) suggestions than a bug report (which was not a bug at all).