Pictures need to have names.
Numbers would also suffice
to make distinctions or for the purpose of cataloguing, but to
characterize and to talk about
a painting one needs to name it.
It could be lapidary and simply indicate what can be seen on the picture:
"Lady with a blue shawl",
In surrealism, a name could have several meanings.
It could bring an additional motif
into play or direct the eye towards some specific direction, even to an erroneous one.
It can circumscribe or be ironic,
veil or unveil.
It can simulate or disappoint,
be banal or poetic.
It can clarify or be a play on words.
We often take a long time to come up with the right name, since it is unfortunate when a picture ends up with an unfitting name.