I can't be positive. It looks to me like you can see footprints coming from the bottom left corner of the thumbnail and ending with the "object." However, in my searching, I have also come across signposts with triangular signs that better match the shadow. Of course, in my book, "person patrolling desert" makes a much better headline than "triangular signpost just standing there." ;o)
Either that or the guy is walking very, very slowly...
What I wanna know is why is there a sign out there in the middle of nowhere and what does it say?