The not looking at porn part first relives you of the addiction to it, same with any addiction you stop constantly thinking about it. It reduces the amount of dopamine required to be happy, so you can be happy again with simple things like hanging out with family, going for a hike etc. Quitting also helps with memory recall, creativity and reduces anxiety.
The not ejaculating part increases your drive to accomplish your goals, also give you constant energy, and even gives you and edge in workouts. Your body isn't trying to make new semen constantly, which is taxing on the body. It's sort of like when you feel slow after eating a big meal, your body is using up resources on digestion, same with your body using up resources creating new sperm.