Update: Now Vint Cerf
Google today announced their latest
April Fools jokes, where you can take selfies and set them as your Gmail background. Katy Perry is currently the one showing up now under the "Most Popular section" if you enable it when you logon to Gmail.

Below is an excerpt from the official article explaining what a "Shelfie is"
"You all love setting selfies as your custom theme in Gmail, but you’ve told us there’s one major problem: there isn’t a way to share your selfie with others. As the pioneering platform for selfies, Gmail is committed to being at the forefront of innovation in the selfie space. And we think it's a tragedy that your handsome hair, luscious lashes and beautiful brows have been trapped in your own inbox. Until now, that is. Today, we’re proud to free your selfies by launching Gmail Shelfie, the SHareable sELFIE."
Read the rest of the article
here.
Source:
Gmail Blog,
Twitter, and my inbox.