The two meanings of -- as itself, and as a shortened form of (see the definitions above)-- both work here to create an alternation of possibilities (almost like a juggling act) in the first line. The two meanings, which are basically those of 'whereas, since' and 'although', are opposites: the first one claims that B happens because of A, while the second one claims that B happens despite A. It's also possible to argue that 'whereas, inasmuch as, since' and 'to such an extent' have a nuance of difference, with the first one emphasizing simple causation and the second one emphasizing what might be called quantitative or accumulative causation.) For more on , see 1,5 . The first reading of 'whereas, inasmuch as, to such an extent, since' (1a) emphasizes the causal effect of the turbulent motion of the glasses, which seem to be waving and swaying as though they themselves are intoxicated. Thus they resemble the constantly moving glasses displayed by a 'glass-player'. By contrast, (1b) asserts the power of the glass-player to keep the glasses in control. Although they're moving and swaying back and forth in almost an alarming way, a real professional knows how to allow for such movement. (Bekhud Dihlavi describes the nature of the performance.) We know the glasses aren't going to fall-- it's all just part of the skillful act that the 'glass-player' is performing. If the glasses are metaphorically drunkards, the carpet is metaphorically a 'glass-player'. And of course, this vision of the room as swinging and swaying would come very naturally to someone who was intoxicated. graphics/movingglasses.jpg