1. The lighting is good as well as the background and pose, those three things are also needed in a good photo as well as portrait.
2. I would have them stand against a plain background so that they would stand out more and there would be nothing distracting to the eye.
3.The pyramidal composition is used to draw the person’s eye up from the thicker base to the thinner top where her face and smile are.
4. The background is important, it gives the viewer something more, it givs a setting to the paintg so you get a better feel of the mood. If behind Mona Lisa was an alien invasion instead of a peaceful countryside the whole thing would have seemed a lot different.
5.A shadow outlines the important spots on a painting, like how the outline her face, this draws the veiwers eye to the brighter spots on the canvas making for a prominent focus point.
6.Clothes are another element that can be a real distraction in a portrait. Take a lesson from Leonardo and use clothes that fit with the subject and give them context – but which don’t distract your viewer.
8. With the columns missing there is nothing to frame Mona Lisa and say that she is without a doubt the main point of this painting