You would. Just go to the bottom of the wiki page, where there's a box, and click 'browse'. Select the picture you want from where its saved on your computer, rename it for cathug (because otherwise it's probably going to have a very long name) and add, like it says, .gif or .jpg, whichever file type it is. Then just click upload file and you have a link to the picture on the 'edit wikipage' screen.