NYC based photographer Daniel Schaefer posted on Instagram an image of a disguised lens he's testing for Lomography. The front of the lens is brass, but too small to be one of their current Petzval lenses. He recently did a review of their Minitar-1 lens, so it stands to reason they'd throw him other lenses to test. Schaefer has also tested for Leica and Sony in the past. Stay tuned for more information.
Update - here is possibly another photo of the mystery lens:
A photo posted by Daniel Schaefer (@outlierimagery) on
Some of the latest pictures posted on Tumblr are most likely taken with the new lens.