I'm sure it can (although I do not have any experience with PhotoBucket), all you need are two different sizes for the same image. If Photobucket does that for you great, otherwise you'll need to create a small image and a large one.
You can likely get crafty with the code here to scale down a large image but that would not really do anything good as it would still take a good amount of time to load for people with slower Internet connections (The main reason I refrain from posting images that are large).
