It's WinMac (as evidenced by the URL) - some hacks that let your windows machine look like various flavors of the classic MacOS

Aha... so, yes, a terrible Photoshop job. :) The progress bars are particularly galling - they don't even line up with the frame properly.

Because of the pixels? This OS was before my time so I can't really see your objection here.

*I exaggerate a little, but I really didn't have a computer until right around this time, and it wasn't a mac.

Probably because it is running on a Pentium? Perhaps it is an emulator or a Linux theme?

Check out the root of URL for this image (http://winmac.emuunlim.com/).

Dead giveaway: the dotted line around the folder name for "Apple Extras". That's some Windows UI right there.