Very nice cardinal shot! I would like to have seen just a tad more space in front of the bird and on my monitor the eye looks very red for some reason. Other than that nice sharp picture and I like the snow flakes in the BG :)
Your bird is very sharp as mentioned, good BG, head angle, perch scale good.
As Colin mentioned, the whites on the belly are hot. I pulled the recovery slider in ACR all the way to 100, and there are still some hot areas. Certainly worth another look at the raw file to see if you have more detail there that you can recover with a different conversion.
Lovely capture of this lady. Great pose and amazing. My eyes are asking for a tad more space. I think you could easily recover the whites here. I love the way her belly lights up...just would like to see it a little less light. THe snow really adds a lot to this photo.