At least, Jaron Lanvier calls it "art". Cephalopods are a class of mollusks containing octopus, squid, cuttlefish and nautilus. Their means of communication is so different to ours that Lanvier used it as an example when he was interviewed about what the future could bring for mankind. Maybe communication will be enhanced, he thinks, pointing to cephalopods.
Take a look at this page and see them in action (there are two movies on it, refresh the page to see them again). You'll see that cephalopods can show amazing stuff on their skin: moving patterns or, chameleon-like, the colours of the surroundings. Researchers know that the patterns are used for communicating with mates or prey. It's an interesting way to show what you're up to and the researchers even like to compare it to humans:
"Although there is no evidence that cephalopods communicate symbolically like we do, there are other forms of communication that we have in common. For example, cuttlefishes gesture with their bodies by striking specific postures that signal their intentions. Humans also gesture and assume postures both to signal intentions and to reinforce what they are saying. Cephalopods use gestures or postures to reinforce body patterns in a display. Humans blush when they are embarrassed, ashamed, or sometimes just anxious. The mechanism of this response is different, physiologically speaking, than the body color changes of a cephalopod, but they still communicate an internal state of being."
Cephalopods seem to us like weirdos from another planet. But still, they live on the same planet as we do. While we're being naughty in envisioning the future, why not imagine us using displays to communicate feelings? Blushing is so old-fashioned... :-)