I would assume they have lights from above shining down at night.
That is not a shadow from a sun or lights...it has to be colored vinyl or paint to create that, go outside with a letter and check out the shadow it cast.
...it is a shadowA google image of the building.
http://maps.google.com/maps?q=1703+...n=0.000717,0.000728&oe=utf-8&t=h&z=21&iwloc=A
The two classic criteria for a sign, any sign, is that it be at once readable and handsome if not beautiful. This one fails on both counts. No one reads shadows and the effect is butt ugly.