Anytime that you can do basketball shooting drills that put pressure on the shooter you are working on the mental side of shooting as well. You will never be able to fully simulate the feeling of shooting a big shot in a real game but if you can train your mind to be mentally tough when practicing you will give yourself a better chance to hit that big shot at the end of the game.
This basketball drill will also help you to work on your mechanics and muscle memory by getting you a lot of reps at the same type of shot. Also, by having to hit 3 shots in a row you train your mind to expect bigger things. It becomes not that big of a deal to hit one or two shots in a row in a game, because you are used to hitting 3 in a row everyday.