To upload a photo, you need to access the files in the hard drive. But the ipad is quite a sandbox. Each software as its own area for its datas. There is quite no communication between softwares, only with iTunes, and not for all of them.
may be you can use iPhoto, or files to try to see if the search box is able to exchange datas with them. But it's not sure.
the best way is to upload photos with a PC, and after use iPad .... I will try this by myself this evening and will come back to you later.
