I planned to take the above photo for this exercise. I think there may be even more implied lines than the ones I have already indicated. We tend to understand the way the painter works and therefore we make certain associations with our mind. We know he will move his hand from left to right in order to paint, he will use more color and therefore he will do another movements towards the color palette.
The strong eye contact is apparent. The two figures are standing in such a way that a balance is created by their shapes. I have indicated the lines that were prominent to me.