Stuff

[Glam Grimfire]

what they're talking about specifically, is that it's fairly obvious you used the copy and paste tool in paint on a specific resource of snow you had made and then pasted it over the lower branches, with a little editing around them to make them blend better. the branches on your tree also look more like pipe cleaners, so perhaps you studied this tree from a photo? (at least the branches) pixelart is all about stylization of fine detail to make it more evident, so perhaps looking at some other trees by other pixelartists would help