Why are film cameos called cameos? In which sense do they resemble cameo brooches? In both meanings of the word we have a human figure. Are they similar in their brevity of appearance? In their ornamental function? In their silence and hieratic attitude? Or are they comparable in their value (jewels are valuable, famous people are important)?
I have already checked several etymological sources. They differ. I’m looking for your opinion. In what do you think film cameos and cameo brooches are similar? What do you feel is the key element in common?
To try to further clear my question: I’m debating in another (Spanish-language) forum the anglicism “cameo”, which Spaniards use but ignore is related to cameo jewels (“camafeos” in Spanish). To most Spaniards cameo means nothing except cameo films. I’m trying to find out the connotations anglophones bring to their mind when they use the word in the cinematographic sense, connotations that Spaniards are unaware of, to show how in this specific case (not in most others) the adoption of this anglicism is not enriching Spanish language.
But maybe this is not a good question anyway.