I can at times see the bulging, but if I look at it long enough, or look away, I can see the craters and canyons, and then it will switch again. The phenomenon has been discussed on CN and Wikipedia. Interestingly, when you see the "lizard" the sun appears to come from the right of the frame, lighting the lizard's right side, but when you see the canyon, the sun comes from the left, lighting the right canyon wall in the frame, and shadowing the left canyon wall. Amazing how our brains work. When search this phenomenon as it relates to other images, I came across this really cool video from youtube: Clear skies!