Screaming: Words speak louder than actions ("Actions speak louder than words")
is a structure that imitates OP's example of "A word is worth a thousand pictures", then it is a
Transpositional pun (Wikipedia)
a complicated pun format with two aspects. It involves transposing the words in a well-known phrase or saying to get a daffynition-like clever redefinition of a well-known word unrelated to the original phrase. The redefinition is thus the first aspect, the transposition the second aspect.
"A hard man is good to find." - Mae West
"No Left Turn Unstoned"
TP on UNCF's motto, "A Mind is a Terrible Thing to Waste."