Observing Mona Liza it can be clearly seen that she has no painted eyebrows. I was for many years a lover of Leonardo Da'Vinci work and I admire and researched his work. When I bought a book from Taschen about Da'Vinci I looked at every drawing and painting closely when I reached at a drawing I realised it looked like Mona Lisa painting. If you have a few 3D skills and a bit of imagination you will see it too in the following picture, where I set the two side by side comparing sizes and locations of each of the details.
Thanks for reading,