Candid black & white photos of kids playing on the beach at sunset are timeless. They are soothing to look at. There is a romantic feeling to them as well. Over the years I've looked at my old family B & W photos and noticed all the details in them. Maybe it's because looking at color photos emphasize color more than the details of the objects in them.
In this shot, my eye is drawn to the sun shining on the beach rocks and pebbles. I notice the ocean water on the surface of the wet sand. The action of Mom looking at what the boys are doing while she is walking towards them, the boy crouching while scooping wet sand along with the incoming waves crashing as they hit the shore, and the beautiful geometric line the people in this image create, additionally adds motion to the photo.
Having a good amount of bokeh (out-of-focus) in the background in this shot is important because it emphasizes and defines the subject (Mom & boys) with clarity. Softening the waves and land in the background gives this image a very nostalgic feeling...timeless! There is something to be said for simplicity.