The camera I used for these is a Canon Rebel 3Ti. The pictures I take with my phone are just about as good. The key is getting good lighting in both cases. The pictures were taken on a bright, overcast day outside...kinda gives everything that lightbox look.
....and getting them to sit still. Put a hide down on the surface you are going to take the picture on, let the snake go inside and settle down for around 15-30 seconds....then pull the hide off and take a few pictures before it decides to bolt...ha ha.