If this is supposed to face Mecca, then I'd say the designer goofed by confusing the crescent's rear with its face. The 'qibla' is the line pointing along the shortest distance to Mecca, not the other way around the world, and off the top of my head I don't see a rationale for why an arc would ever be considered to 'point' in any direction except for its opening. Then you look at the fact that people will be entering from the outside of the arc, driving its outer edge, and looking toward its interior... they'll generally have their backs toward the east and 55-degrees.
I'm not sure visitors will sense any of the crescent-ness of this, much less its orientation if it is sufficiently large. Already the endpoints are somewhat ambiguious on the plan view. In the grand scheme of things I'm much more concerned about the WTC memorial than a monumental inkblot test.
There are 2 ways to Mecca...the short way and the long way...the long way is the opposite ot the short way bearing...