I have always considered art to be an expression of one's mind.  Artists each have their own style and approach to a subject, freedom of expression being top priority. Buddhist art is very unlike western art.  Much of western art tends to be a reflection of the individual ego, one's creative whims guiding the brush, the present emotions expressed in the colors.  In Buddhist tradition, holy figures such as Shakyamuni Buddha are drawn using specific sets of parameters (iconometry).  Within these parameters, a proportional unit of measurement (sor) is used to assure proper representation of the Buddha's enlightened qualities.  At first glance there doesn't seem to be too much room for an artist's individual expression but the individuality of the artist isn't the point here. The visual expression of Enlightened qualities is the point and the tradition of Buddhist iconometry keeps this vision alive. 

  Kuntuzangpo
Padma Gyalpo
  Loden Chokse