|Greetings from the Critique Club!
I like the impressionistic feel of this shot, falling snow, dirty window and all. And yes, wildlife don't take direction well! Looks like you shot on a very murky winter day, when the sky is a flat monochramatic grey, and a flash would frighten off the bird.
Like the way the branches help frame the cardinal. Your settings and composition and fine for such a tricky shot, you scored poorly mostly due to ambient lighting than anything else.
FWIW...I live in an old schoolhouse, the kind that has three gigantic windows down each long side. I scrubbed out the window that would give me the best shot of birds with vinegar and water, and removed the window screen. This gave me the chance to get shots of the birds through almost-perfectly clean glass. May want to give it a try.
Overall, a great attempt in terms of concept, execution needs a little more work. Keep shooting!
Feel free to PM me with any questions,