We do say that a picture paints a million words.

Most times a simple picture clearly says a lot of things, but when it comes to religious picture there are lot of symbolisms involved so it is like reading a book.

Impressionists do not require specialized knowledge, nor do abstracts

To read art the knowledge of symbolism is every essential.

In the western scenario a dog would mean loyalty bi one does not recognize it unless one has that knowledge.

St.sebastian is shown with arrows,

Time – derived from tempus which is masculine so when personified time becomes a man, with a beard, winds and an hourglass.

So a painting depict a marriage would show, a dog, for loyalty, father Time combination to convey longevity and loyalty in the union  a background picture of St.Margaret ( if one hopes for pregnancy she is your patron saint). A bowl of fruits somewhere to symbolize prosperity both economic and biological

A lit chandelier to symbolize the marriage is not consummated, or a blown candle if it is consummated. This is a carryover from a northern Europe tradition.  It is evident in the Immaculate Conception paints of that period, where Mary is shown with a blown candle to depict her mystic union with god and that she is carrying his child.

Once one is able to decipher the codes then  each painting will narrate its story or decode itself.

Hence  a picture paints a million words.