I noticed this same thing, almost identical pattern. There is no spotting on my garage floor, however, which leads me to believe it's just "seeping" or "weeping", but not actually leaking.

 

Mine was like this when I crawled under there to change my fluid a few weeks ago. I cleaned it up, drained and resealed. Haven't seen any evidence of seepage again yet. I used the Grey Gear Oil RTV and waited a few hours before refilling like recommended...