Yea, looking at the ref image, you can tell the material is fairly thin as you the folds tend to be very sharp and creased...something to keep in mind.
I'm really digging the detailing on this. (That ceiling!) The lighting appears a bit sharp, with lots of areas that are very dark overall, as a lot of that lovely detail is getting lost.
Thats because the normal map is made out of gradients. If you want fully sharp lines, you could feed the result into a "round" node for example. or an IF.