I'm not sure that's a real "design world" term. I may have just made it up. Or coined a new trend. If there was a Facebook button, I would push "like".
They reminded me of these, that I came across at Urban Outfitters a few weeks ago:
I love the idea of injecting a little bit of art into an everyday item as simple as a pillowcase. I'm even a little bit jealous I didn't think of it first.
PS - you really should check out the rest of the Salvation Jane range. It's really pretty. I can definitely see some Personality Pillows being used in a bedroom makeover at the SD Interiors house.