I think that it is possible that the photo might be of Vincent.We have to remember that he was living with a bad case of depression,probably hunger at the best of times-and the hard core drinking of an alcoholic.If I could assume -he probably earned his keep in many places working outdoors under the hot sun as a labourer,where the suns rays can prematurely age skin.Not to forget,his system was also drained by the std's of his time-all helping him age beyond the average stereo typed 30' something middle class male.The eyes in the photo appear to be light in color,which can belong to a red headed person.

I think we have to remember that life is not about the amount of breaths we take,it is about the amount of times our breath was taken away.I believe Vincent tried to share that with us,and if he used a grid,or a photo or even a chunk of glass to help him on his self taught journey-so be it.Let sleeping dogs lie.