Because if our system goes this way, it's going to produce on average, less moles of molecules than on this side. So, our system will try to counter the increase in pressure by decreasing the pressure by going this way to decrease the number of total molecules found in our system. If we have less molecules in our system, that means less molecules are colliding with the walls of our container. And so, our overall total pressure is less. And finally, let's look at how concentration affects our equilibrium of our reaction according to Leslie Lee's principle. Now, let's look at the same reaction.