[Butterbeer]

The other option I’ve found is when you create a post on Facebook and click on Photo/Video, it will open up the Finder window, and at the bottom of the left hand bar (with the folders, tags etc), it says Media, with Photos and Movies under it. If you click on Photos, it will show all you pictures like it does in the Photos app, so you can select an album, place, moment etc.

From a little google, that seems to be the only other way of doing it