dpreview member asked how to add snow to a picture.
This is one way to tackle the job.
Open separate image of snow to use for snow source
Create new layer on the target image (bird)
Use snow picture as source for cloning into the bird image
I first cloned some out of focus background snow, then worked on
a couple of branches in the forground.
I rotated the source image to orient branches with those in
the bird image, then cloned on top of the original branches.
Then create a layer mask on the clone layer to blend and soften the cloning edges.
The highlight in the ice to the left of the bird seems to
pick up the bird's color. Nice touch, but totally coincidental.

original image by Charles Corker