Notice that the background is transparent.

If you had a slow connection, you would notice that at first the image would be blocky and unclear.  As the image keeps loading, the image will become clearer.

This is showing taking the image with a original color depth of 256 colors and reducing it down to 4 colors, the file size became much smaller and the image quality did not degrade much.

The JPEG format is not recommended for line and cartoon art.  Notice that the .jpg file size is much larger that a .gif file size.

The JPEG format is not recommended for line and cartoon art.  Notice that I had to use a compression factor of 80 in JPEG format to get the file size down to a comparable GIF file size.  Notice the poor quality of the image.