Does your filename start with tn_? Could you open it without un-zipping it first?
If the answer is yes, you've downloaded the thumbnail or the slightly larger preview instead of the full-size image.

Image is large and pixelated

When you open a 300+ dpi JPEG or GIF in a raster image editor such as Photoshop or Paint Shop Pro, the image may seem very large and very pixelated. This is because most screen settings default to 72 dpi (dots per inch), and your editor must spread the pixels over a larger surface area to conform to this setting. To view your image at its correct settings, you'll need to reset the resolution to its desired dpi WITHOUT resampling it. See your editor's help documentation for instructions.

EPS image is black and white

An EPS has two components: the image itself and the preview. The black and white, jaggy image you see onscreen is the preview. If you have a PostScript-compatible printer, it will read and print out the actual (color) image. If your printer is not PostScript-compatible, consult your software's help documentation to see if your image editor will accept WMF - the screen display for this format will more closely resemble the printed output.

Animation isn't animated anymore

You've probably opened the image in an editor that doesn't support animation.