"muralism", a new term for me I must admit, I understand it as an art that is between the graffiti culture and a more established sense of art ( I am assuming this from the "-ism" used here).
Thus, between a culture of non-conformism and anti-system and the culture of the establishment, of art galleries, and museums.
Now, I think this is interesting, because Dorje Shugden is an established Buddha, proven so, and yet he is made to venture in the realms of "non-conformism" and "anti-system" because of the ban enforced by the "system", while, eventually he will be recognized by all and will achieve the place he deserves, just as graffiti has made it into the world of recognized art forms, or "-ism's".