Two young girls, one wearing a pink jacket and the other in a dark-colored jacket, are playing in the snow and having a snowball fight in a clearing outside of a wooded area.
Two girls are playing
Girls playing in the snow implies they are playing.
Sentence 2 restates Sentence 1 with less detail: two girls are playing.
Sentence 1 indicates what the girls are playing and where.  Sentence 2 only indicates the girls are playing.