Answer yes... But I can't find a way to do all of them in one go, only one at a time, which is a real pain.
See the screen shot below - when you open an individual picture on Dropbox, you can choose the "export" option which puts it back on your phone.
When you select multiple pictures, I can't find an option to export.
This may be by design, or perhaps I'm missing something.
If you don't have many pictures though exporting them one by one may work for you?