French or English zograscope print c.1745 

A zograscope is an optical device for enhancing the sense of depth perception from a flat picture. It consists of a large magnifying lens through which the picture is viewed. Some models have the lens mounted on a stand in front of an angled mirror. This allows someone to sit at a table and to look through the lens at the picture flat on the table. Pictures viewed in this way need to be left-right reversed; this is obvious in the case of writing. A print made for this purpose is called a vue d'optique or perspective view.  

linen backed and missing pieces at the borders

re. Wikipedia