I saw this painting in the National Gallery of Scotland in Edinburgh and I looked at it on the gallery wall for a full half hour. The light is superb. You can see the oil that she's cooking the eggs in, and sense it bubbling as you look at the painting. 

 

 

Essentially, what I aim to do when I paint, is to paint light on surface, and that is what Velazquez has achieved here. It's an extraordinary piece of work.