What are Maid Job and Dress Collection in the gallery?
Viewing post in Yorna: Monster Girl's Secret comments
The collection is a showcase with all dresses you can get in the game with the last update around Yorna EX version. I'll refresh it once we'll reach the final update for the game story-wise and you'll get it unlocked after getting any ending.
As for the maid job scenes - Ada needs to "work" in the baron's mansion and serve guests. Getting H scene there will unlock them in the gallery. Any pleasure score will do.