No, I don't think it is, but I'd be curious to hear what people think it is.
The photo in question is AS17-146-22293. Just to the right of the rock is a dot of light. In the hi-res version at ALSJ it appears to be two dots. (The dot is also visible in the LPI low-res image, so I assume it's not an ALSJ thing.)
However AS17-146-22294, which must have been taken only a few seconds later, doesn't show the dot.
Any thoughts?