Jamo is correct, if photos are coming from a photo storage site like photobucket, picasa etc the photo will be displayed on the forum at a size no larger than 600 x 600, but if you click the photo it will enlarge to full size, a second click will reduce it to the 600 x 600. Naturally, if your original photo is less than 600 x 600 it will only be displayed at its original size.
Des.