You can apply it to a single folder or as many as you want all at once. Just "lasso select' (or ctrl-click or whatever you want to do to highlight the folders you wish to change), then go to properties. You can change all the folders you want at the same time.
For example, let's say I want program files, users, and temp to all be considered picture folders, and use that template. I can select them, go to properties, and change them all at once.
Nothing is useless :)