Rearrange photos in albums
If you're talking about an album on this site, I don't think you can. My recollection of the one I made (and later deleted) is that the interface is really cumbersome, and getting pictures in a particular sequence took several tries.
The viewing interface is just as clunky, so I decided in the end it wasn't worth the trouble.
Putting them in a thread is another option, depending on what your purpose is in sharing the photos.