Yes... what he said
Newbie'* need a "safe place" to post as a practice and to check out their signature pics. But no, you don't need to post new each time.
however, when you are re-sizing your photo'*, you may run into a problem with Cache'*... I can remember downsizing a pic... looking and finding it was the same darned size... so I'd resize it again... ended up with a tiny thumbnail pic because I couldn't see the re-sizing going on. Turned out the pic was being saved in a cache (???) and I had to close out photobucket and start over to view it properly.
At any rate... Haro fixed Doug up with a pic and it looks great....