The new gallery has two main sections, 'Categories' and 'Albums'.
An album is a place which can only be uploaded to by the person who created it.
This is fine for your own small collection of things.
You have full controll over it.
You can make it yourself in the gallery.
A category is a place where anyone can upload to.
This is great for an anime series or a character, so that everyone can upload images of that series or character as well and it can grown from everyone's images.
This is like a shared album, its the best for everyone to use.
Staff & Mods have to create it.
If you would like to request a new category, please make a post/reply right here in this thread