Reflecting of the Triple Gem helps remind us of our inner refuge and what we are capable of doing.
Reflecting on the Buddha helps remind us of the greater human potential. This helps us to bring forth courage to reach within for those good qualities that we have within ourselves and develop our human potential.
Reflecting on the Dhamma reminds us of the methods that we have to develop that human potential to a higher level.
Reflecting on the Sangha reminds us that there have been millions of people throughout the centuries who also value this path so that we don't feel alone in our practice. Many times, as we develop in our practice, we change. This can be threatening to people who may have known us before and sometimes they can not understand us. Sometimes due to a feeling of being different, meditators will reach back to the known because it's familiar, and because they are afraid of loss. But by understanding that millions of people throughout the centuries have valued this path, they have walked this path before us, and by imagining them with us we realize that we're not alone at all. There are millions of others who value the same path.
So by meditating on the Triple Gem, it helps give us the strength and courage to be different and continue to walk the path to the ending of Dukkha.