Proskynetarion

A proskynetarion (Greek προσκυνητάριον (from: προσκύνησις) meaning "oratory" or "place of worship", plural proskynetaria) is a monumental icon of the Eastern Orthodox Church usually depicting Christ, the Virgin Mary, or the patron saint of a church.

a Serbian Proskynetarion

So-called Warsaw Proskynetarion (c. 1795), National Museum in Warsaw

They were usually made of mosaic or fresco in a marble frame and placed on the piers separating the parts of a templon in a Byzantine church, though proskynetaria of patron saints were often in the narthex or on the nave walls.