I found that if you go to Google images and type in “Bridge of Sighs” you can see how Sargent interpreted what he saw. I found this very helpful. In this painting I noticed Sargent left the head off the rear gondolier and the mind fills it in. Notice how Sargent makes the viewer feel that they are not just a casual observer, but are actually in the gondola as it heads for the bridge. He has captured the essence of the moment. You can feel the warmth of the sunlight on you unless you are protected by a parasol like the two ladies on the passing gondola. From a purely technical observation, notice how he uses the principle of warm advances and cool recedes from the wonderful wash on the shady side of the buildings. Notice the warm reflected light under the bridge. Even there, he uses warm tones up front and cooler ones in back. Look where the real concentration of dark darks are. They are at the foot of the gondolier, exactly where Sargent wants you to look. The white clothing of the gondolier sharply contrasts with the dark shadow of the building. We intellectually know that gondolas are black. The amateur painter would have painted them dark. Sargent paints what he sees. The gondolas are black, however they are like Chinese lacquer and highly reflective. That is why he painted the left side of the foreground gondola reflecting the sky and the sun bathed building on the left and the right side reflecting the shady building on the right. Also the passing gondola reflects the water. This is painting what you see, not what you know. Notice the pole the gondolier using. It appears Sargent scraped with a knife the part that overlaps the building, lost part of the pole and then picked up the dark stroke that complete the pole. Here again the brain fills in the missing section.