Photo sharing service Instagram is sending out invitations to select journalists for an event to be held on Thursday, December 12th at 10 a.m EST in NYC. Like most press invites, the unusual invitation provides only a mystery and virtually no clues on the topic that Instagram will be announcing. Bucking the trend of sending out press invitations via email, the Instagram invitation was sent via snail mail and was a full-blown package, not just an envelope. CNET provides a detailed description of the contents of the invite,

“The package, wrapped with brown paper and a white ribbon, contained a wooden block, 4 inches long and wide and 1.75 inches thick, covered with a printed Instagram shot and a slot in the back so it can be hung on the wall. The included note invited the press to “share a moment with Kevin Systrom and the Instagram team.”

The invitation provides no clues on the announcement itself. What does Instagram have up its sleeve? Recent rumors suggest the company may add a private messaging feature to its photo sharing social network. Others speculate that the use of ground shipping to send the invitation hints at a photo printing service that would allow users to send and receive prints via mail. So what do you think Instagram is going to announce? Chime in the comments with your ideas.