This doe and I noticed each other at the same time. The doe froze, her left hind leg lifted slightly as she was taking the next step. I lifted my camera, slowly, and it began making a clicking noise. It seemed to me that the doe could not quite make out what was that somewhat unfamiliar presence on the trail. (Deers' eyesight is only about 20/200, so this is understandable.) The slight movements and clicking sounds added to the mystery.