Take the example of google search for images. In the search , enter Painting. You would be listed with the resultset. In the left navigation you would see some categories like how u want to filter your search. So you can filter the search by view, size , color, etc which ever is applicable. The categories which you see in the left navigation pane is called facets ie.,different faces to search for a particular thing. This is facet testing. You can refer the site www.macys.com where you would see the implementation of facets.
Hope this would help you and others let me know if my reply is correct.