Just one well known difference: Human have two eyes and we use the difference to determine distances. A photo is flat. Another difference: In human sigth you c

Just one well known difference: Human have two eyes and we use the difference to determine distances. A photo is flat. Another difference: In human sigth you can only focus on the center of the vision field, while on a photograph you can look at unfocused points and observe the distortion on the edges of the picture. Human observation (like looking at the bridge in the pic) is really a series of observations where we move the focus.