This is a Carthusian monk. The two fingers are pointing at the silence vow and the work vow typical of these monks. He's also pointing at St. Bruno's image on the door. In fact, this life-size painting is in the cloister of a former Carthusian monastery, built transforming part of the tepidarium of Emperor's Diocletianus' Baths. The cloister and a church using part of these ancient Roman buildings were designed, and partly built by Michelangelo, when he was about 80 yo. Is the monk a 2D, a 3D or a 2.5D? 2.5D (two-and-a-half-dimensional), also called pseudo-3D, is an informal term used to describe visual phenomena which appears to be three-dimensional but for some reason isn't completely so, be it for not being constituted by true 3D entities in the case of graphics, or not allowing full 3D movement—typically restricting it to two dimensions—in the case of videogames. As a matter of fact, my photo actually reproduces something which is an illusion using both 2d and 3D elements. In fact, the 16th century artist exploited a part which is 3D, that it the marble doorframe, the step and a wooden door (transformed into an illusory shelf-case with false objects painted inside it). He created a false 3D image, using architectural items such as a real door which had been closed! This technique was very fashionable during the late Renaissance, and later copied at least until the 18th century. It's interesting that the artist decided to introduce an element of fun by means of a trompe l'oeil(at that time they were crazy for practical jokes) within a very stern context such as the Carthusian cloister. I don't know whether it was intentional or not, but when the cloister became part of the huge Museo Nazionale Romano, which includes Diocletianus' Baths and other palaces, the curators put pagan, naked statues close to the monk! Thank you for your kind comments.