Real strength is never manifest. In fact, this quality is such exactly if and when it is not evident. Whenever it is (seems) clear and patent, it is only a knock-off, a travesty, an imitation. Therefore, not being apparent is part and parcel of its real nature. Moreover, whoever is really strong and powerful does not need to show (pretend) such a capacity. Whoever is powerful only needs to act successfully according to his strength. For instance, when forced in a physical confrontation, he who is strong needs not to show his muscles or behave in other ostentatious ways. He needs only to use his force in the most effective and swift way. Strength has to do with immediate results and it actually rejects theatrical representations of any kind.
Real strength is never manifest. One of the best signs (evidences) of real strength is SELF-CONFIDENCE. Indeed, if you are incredibly strong you must feel strong and you inevitably possess self-assurance. Furthermore, an undisputable mark (proof) of self-confidence and self-possession is CHARISMA as the capacity of being perceived strong and credible without the need of showing these qualities. The best people are almost always unassuming, modest and self-effacing. HUMILITY is a virtue.