icon vs photograph

icon

noun
  • A small picture that represents something. 

  • A person or thing that is the best example of a certain profession or some doing. 

  • An image, symbol, picture, or other representation usually as an object of religious devotion. 

  • A type of religious painting portraying a saint or scene from Scripture, often done on wooden panels. 

  • A word, character, or sign whose form reflects and is determined by the referent; onomatopoeic words are necessarily all icons. 

photograph

noun
  • A picture created by projecting an image onto a photosensitive surface such as a chemically treated plate or film, CCD receptor, etc. 

verb
  • To appear in a photograph. 

  • To fix permanently in the memory etc. 

  • To take a photograph (of). 

How often have the words icon and photograph occurred in a corpus of books? (source: Google Ngram Viewer )