Arghhh. I'll admit at 6'7" it must be hard to find a frame that fits, but to me this looks like pushing it a bit. The seat post looks overly extended and such a long steerer tube can't be good. Hopefully the rider is not too heavy!
The line on the mast could be a "don't go any lower than that". If you search for pics of this model, the line is visible on a lot of them.