Incline Barbell bench press with imbalance weights is an unorthodox chest exercise which is used to help even out the strength ratio in the chest. As you will know, one side of your body will be stronger than the other and that may never change. It is simply because of how we think. If you favor your left hand it will always be a bit stronger than the right. This is one of those exercises that helps balances the strength.
You will find that you have to tighten your core for balance, this means that your core will get a workout in a way it is not accustomed to. That's all for the better!