As Sarah said, the main canvas renderer does not support animated GIF files, it's a limitation of the technology. Also, for example, the image uploader currently strips animation from GIFs as well, so the only way you would see animated GIFs like you are seeing is from things added from the Web Search. Other places in the app like the ones you pointed out do happen to support them to some degree because it's a different type of rendering. But at any rate, officially we don't support animated GIF images at this time.