To start off, you picked a fantastic subject with a great setting indicated in the title.
Vision - You picked a great title for this image. "Window Flowers", along with looking behind the flower, portrays a sense of looking in from outside, where rain and clouds influence the mood. You've given us a great feeling with this.
Originality - When flowers are photographed, most are mixed with cheery or neutral colors. I enjoy how you've brought a melancholy tone to the image. Also, looking from behind is a unique sight among floral photography.
Technique - this photograph shows that you have a great eye for interesting angles and surroundings. You've also brought out the beauty with a crisp focus on the closer part of the flower. The farther part being out of focus helps with the idea behind the shot. The only criticism I have here comes in two points. 1.) There is something appearing in the upper left-hand side that I presume to be another flower. While this may fit the theme well (as something out of reach), it distracts from the main focus. 2.) You have an *excellent* eye for the rule of thirds, but the stem seems to divide the image. Maybe if it were tilted down toward the lower, left corner, it would make it perfect. It's a small part, though, so not as important. Again, excellent work with this photo! I like it a lot.