It aint even a photoshop job. They just took some belted rounds and stuck them in the weapon. Just by looking at the 1911 you can tell it wouldn't work as there is no place for it to expel the links after stripping a round. All they did was take the links from a 7.62 belt and link up some .45 ACP ammo. You can even see the rim guide of the link sticking out in front of the round.
In the case of the AR and the bolt gun, they did the same thing. Just took a belt and stuffed it into an oriface of the gun. If you look close the linked rounds are too large to even fit. And if you look closer the bolt is set to eject out the same port the rounds are being fed in from (the ejection port) which might create a slight problem with feeding and ejection.
There were experiments with belt fed ARs, but they took considerable modification and didn't work all that well and IIRC used a proprietary link to boot.