I am wondering if the upper corner highlights had been either down lowere or removed all together. They are where my eye went as soon as I saw the picture. Good job though.
nicely exposed, I'm not a big fan of the subject matter. Other than the nice creases forming a pattern on the umbrella, I just feel like it is lacking dimension.
Some interesting textures here, and I can see why you were drawn to photograph this, although in this instance I'm personally not keen on your choice of centered composition.