Smartphones are sometimes marketed these days as being capable of shooting "DSLR-quality photos." Samsung went a step further: it was just caught using an actual DSLR photo to fake its smartphone's "portrait mode."
Want to see a super early example of a photo being faked through compositing? Look no further than this circa 1902 photo, titled "General Grant at City Point." It appears to show General Ulysses S. Grant posing on a horse with a large number of soldiers in the background, but it's actually the combination of three different photos.
Photo-editing wizard Corey Barker of the National Association of Photoshop Professionals wanted a photo of his house decorated with Christmas lights but was too lazy to physically put up the decorations... so he did it in Photoshop. All the colorful lights and decorations you see above were 'shopped in.