Sentence:  It is customary to distinguish three components in an emblem: the <WSD>pictura</WSD> or symbolic image or picture, accompanied by the preceding inscriptio or motto and the subsequent subscriptio, usually an explication in verse of the idea expressed in combination of the inscriptio and the <WSD>pictura</WSD>. 
Meaning of the word marked with <WSD> tags:  The picture or image component of something, such as an emblem or poem, that contains a combination of imagery and text or symbols.