Wow, strange to see this here. I created a photo series with a very similar title ("Love in the Age of Strong Cryptography"): http://freezine.xyz/0/love-in-the-age-of-strong-cryptography...
I've seen GnuPG-encrypted conversations in "private" Craigslist channels. But no background images, of course. So exchanges are public, but only readable by participants.
At some point, with better technology and bandwidth, those could be thoughts, or even shared reality.