In Opera you can view an image’s complete properties before the image has completed loading. This means you can see the size (in KB or MB) when the image is still in its infancy of loading (slow connections, limited data cap), and you can choose to stop the image from loading if it will drain too much data. No other browser has managed to provide this feature. They will only show the image properties properly after the entire image has loaded, and by then it is far too late.