Applying a layer mask over the unwanted areas of the reflected sky can either be tedious and time-consuming, or simple and fast. I think we all would prefer the simple-and-fast method, right?
Although the area where we need to apply the layer mask appears complex (it's not simply a circle, for example), we can define the area in just a couple of quick steps. Then, with the ideal brush tip, we can trace along the lady's legs and then finish creating the mask.
In the following steps, you will apply a layer mask on the areas that are outside the floor area. C'mon—
Creating a Layer Mask Outside the Floor Area
On the Layers palette, Ctrl()+click on the Gallery layer mask thumbnail to load the mask ...