Most images are NOT on the web or in e-collections. Copyright restrictions, availablilty and other reasons mean that only a fraction of images available are online. Most research images are printed. Locating print sources and scanning is still the best way to use unique images. Copyright generally allows ONE copy of any image to be scanned for scholarship and classroom presentation.
Printed images are indexed. You don't have to browse endless magazine runs or books to find images. Some indexes of print images are even electronic. Most users find that the little extra work spent finding a print image is worth the results.
Art-Specific Subject Headings
Library subject headings allow for any topic to be linked ". . . in art." For example, "Crying in art," "Women in Art," "Death in art," etc. Books about individual subjects in art are usually heavily illustrated.
Social classes in art. Violence in art
City and town life in art Food in art
Blacks in art. Slavery in art.
Books that have pictures in them are described with "ill." in the collation of the book record. If color, it says "some col." Here's an example: