Shadows at Blenheim: low intensity winter Sun

On virtually the shortest day of the year, I was looking at shadows at midday in the grounds of Blenheim Palace with my niece. Look how long the winter shadows are, because the Sun doesn't get high in the sky. The tilt of the Earth means we lean away from the Sun, hence it looks lower in the sky. Your shadow is the sunlight you block. Now your size doesn't change between summer and winter: you must be blocking the same amount of the Sun's energy. But your shadow is bigger so the Sun must be throwing the same energy over a bigger area. We say that the intensity of the sunlight is lower in the winter. In summer, midday shadows are shorter. The same amount of solar energy is thrown at a smaller area. It will have a higher intensity. We are the same distance from the Sun summer and winter: it is the angle at which the sunlight hits the Earth that makes the difference. Here's a diagram to explain it: