"Fake" is a stretch here. Certainly this is not an image that was arrived at by pointing a camera out of the spacecraft window and pressing the shutter button. It IS made from a collection of real images...hundreds of them...composited together to make a single, beautiful image.
It's not "fake" because they tell you, very clearly, that it's a composite.
So - yeah - this particular photo is "photoshopped" and nobody denies that.
However, the photo called "earthrise" that was taken of the Earth from Apollo 8, in orbit around the moon is not. It was taken with a Hasselblad 500EL and the resulting film (not digital) was processed and printed. Subsequent processing of prints taken from the original film have played with contrast, brightness and color balance - and the result is a clearer picture of Earth and a crappier picture of the lunar surface.
This isn't "faking" the image - this is just an artistic choice of how to set exposure settings that your cellphone makes automatically every time you take a photo. That processing isn't making the Earth any more or less round.
Like ALL NASA photos - the original high-rez, high pixel-depth scan of that photo is publically available to anyone who wants to use it...and the Earth is still round.
So - either you're prepared to label as liars and cheats: call all of NASA, and all of the other space agencies, and all of their contractors, all of their crews, all of the technical people at Dish Network and all of the cellphone and other GPS manufacturers and all of THEIR contractors, all of the astronomers and all of the astrophysicists and cosmologists...or you accept the evidence and admit that this is clear evidence of a round earth. You can't have it halfway. Either tens of millions of people are lying to you - or you're wrong. You choose.