Maine Coons are big for domestic cats, but nothing like as big as that in the picture. A friend has three of them so I think I can say that pretty safely. Our two largest cats are in the 10-12 pounds region and a Coon weighing twice that much isn't twice their dimensions or anywhere near it.
The pictured cat is around the size of a small tiger. And the picture has the signs of extensive manipulation all over it. Notice how the fur on the cat's back is in focus then as you look towards the t-**** the fur is out of focus then the t-shirt is in focus again? Absolute giveaway, camera lenses don't make something close to in focus then the mid-ground out of focus then the background back in focus again. They make things around their focal point in focus with things far enough before or behind it out of focus. Basic physics.