What is Velazquez doing in his own painting Las Meninas?

Standing at an enormous canvas, brush in hand, looking directly out of the picture at whoever is standing where the viewer stands - and we cannot see what he is painting, because the canvas is turned away.

That is the puzzle the painting has generated three centuries of argument about. The king and queen appear as small reflections in a mirror on the back wall, which suggests they are standing where the viewer is and that Velazquez is painting them. But the geometry does not settle it, and the reflection may be of the canvas rather than of the sitters. So the picture may be of the royal couple, or of the princess and her attendants, or of the act of painting itself, and it deliberately withholds the answer.

It was also a claim about status. Velazquez spent his career arguing that painting was a liberal art rather than manual labour, and he is wearing the cross of the Order of Santiago - a nobility he was awarded after the painting was made, so the cross was added later, possibly by the king himself according to court legend. He put himself in the royal household, at work, dressed as a gentleman, which was the whole argument of his life rendered as a picture.