They look like they were washed up. In fact, they were stepped out of to better feel the sand with my toes.
Two kinds of sand along the beach. That closer to the surf, hard packed but still supporting as you step. Further ashore, much softer. Your feet settle more deeply and you need to adjust your walk.
More like real life, needing to adjust a little each time as you make your way!
What kind of beach sand do you enjoy?