The image you see is likely internet falsehood designed to create controversy.
The original poster on Tumblr is here: http://day47.tumblr.com/post/15209175576/http-day47-tumblr-com-post-15213853278
The original image posted by GQ is here: http://www.gq.com/women/photos/201105/jennifer-lawrence-photos-x-men-winters-bone#slide=3
While I have no doubt that GQ photoshoped Jennifer Lawrence before they released their photos, it is not obvious that GQ or any other “they” photoshopped her to look skinnier. The animated gif was instead likely put together by someone on the internet to stir up controversy.
What bothers is that this particular image has been reblogged over 40 thousand times, and it took me over ten minutes to track down the original source and how authentic it was, which I have little faith is as much time as other rebloggers took. Which means this image has been going around with people placing the blame on they and them (or the media) quiet likely very falsely (at least in this case).
Some how I don’t even think snopes is going to save us.