Engraving ... tattooing ... themeing ...
IRL we have analogs of themeing our wordress/tumblr/facebook in engravure or tattooing. They afford peacocking of content and its adaptation as we see fit: engraved words or tattooed patterns may be borrowed outright from other sources or more commonly personalized prior to display.
Online, we spend a bunch of time designing sites that look good with as much content as possible; these default themes tend towards corporate minimalism (imagine facebook themed steampunk). Even with our own personal themes, we have to choose either another generic color scheme, or match the theme with a subset of our content.
We don't yet have much ability to modify posted content and our theme so that they match each other. Currently, it's a huge pain to do this with just images. With full motion video and sound, ....
Which then throws us into the dreaded Swamp of Copyright as our notions of personalization (beyond just making a name semi-permanent) typically infringe some copyright holder. Perhaps copyright should go the way of fashion, as Johanna Blakley argues.