The images become compressed and resized so that they display on other devices properly. If you click on the same image from the mobile site, the picture will enlarge and look a lot better. Also if you copy the image code and paste it into a site such as this, the image will display the same as it does on the device. This is the method that I and many others use to post our pictures onto these forums. Some of these such pictures are posted in the social forums.
Posted from my CrackBerry at wapforums.crackberry.com