I feel the same way.
I think its just like that with all ICS. My Galaxy s3 does the same thing.
I read that if you rename the folder to have a "." in the name it doesn't show the pictures. For a example .pictures.
The problem with that is, it seems to hide ALL the things in that folder. So if its a folder with music and album art. It hides the music too.
I would love to know if there is a better solution to this.
I dont use picasa or any other photo apps to even want to see these in my preview.