This is because terminals in the library are currently text-based. For that reason, also, sites chosen have useful text information as well as graphics. If you have a graphical browser, you will see both. You may find a topic under more than one subject. Here are some of the quirks of the Internet that art afficionados must contend with.
Graphics take a long time to load, much longer than text.
The Art History Prof. at XU leaves the university which hosts his site. Anyone can have a web page, and claim to be an authority. Museums, galleries, and individual artists have found a worldwide audience. If you have accessed this site with Netscape or Microsoft Explorer, get comfortable and take a visual tour.