This is painted exactly how I'd do a plein air painting. I like to make a hybrid of elements that are important to an area instead of copy one frozen moment. Using multiple reference photos can get a better feeling for a scene and create a story. I find a sense of motion is introduced when using several photos, much like the experice of being on location.
Copy the demo as is, or try your own version of spliced photos. Remember to pay attention to the right/left side of the art and check to have car roofs, windows, sidewalks, and people's heads consistent. These elements can often grow or shrink and right/left discord can make city art feel unsettling. This issue can also show up when using multiple reference photos. Notice how the images I chose are similar in size of elements and sky 'V' shape. Try to match the sky shape (flip a photo if needed) as this fosters unity of the scene and consistent perspective angles.
Watermedia students NOTES: Start with a light Burnt Umber wash/drawing for rough building placement. If drawing with the brush is uncomfortable use pencil. (I find I need to 'see' the shape and the little lines of pencil are confining, so I rarely use pencil to start a watercolor). Preserve lights with a dab of very light yellow, or use a chip of white artist tape for masking. Paint the sky and have it flow into the tops of the buildings and palm tree (overlap). Next create some orange (mix yellow and red) mid-tones (far distant shapes of church steeple, shop lights, and far buildings/trees). Let partially dry and paint dark buildings with Burnt Umber and Ultramarine mix.