This was a simple exercise with my iPhone in seeing. I photographed the same things at two different times of day, from different points of view.   
  In many ways they are extremely similar: they’re both studies in form and abstraction, with the shadows of the things as the main subject rather than the things themselves (more so of the lamp post than the bike rack, but you get the idea).  
Can you guess which ones were taken in the morning and which in the evening? 

Notice the color, texture and angle of light in each shot. See how the changing light transforms the shapes and makes them look different. 

This was just a quick and dirty exercise, but something I recommend for anyone interested in improving their vision and technique.