i understand your concern this image of adi shankara is just held be to genuine all over india i don't know if it is indeed a portrait of his in fact all the sannyasis monks of the dashanami sampradaya founded by him look the same as he does in this and other pictures with saffron clothes a danda stick and three lines of vibhuti sacred ash so it is very likely that he looked like this but noone can say for sure that this is exactly the way he looked could this be a fair use rationale reference talk