My initial gut reaction to this combination is “choose the path with heart.” The Lovers astrological association is Gemini (air), which is concerned with duality and choice, and Leo (fire) is ruled by the sun, which is all about the heart.But let’s face it, we live in a world where it seems increasingly harder to choose the path with “heart.” How many people have you met who are wildly successful at doing what they love? or have the end all be all of relationships. Thus the Lovers is always faced with the trials associated with choosing. Coupled with Strength however, trials faced are overcome with one’s ability to tame the “beast,” which represents untamed creative impulses, unchecked ego, imbalanced 2nd chakra business….
There are two images that strike me as a means to reconciling this idea of successfully navigating this world with “heart.” One is the woman looking up towards the heavens, she is the feminine looking up to an angel (archangel Raphael), while the masculine (the man is looking at her) is guided by her. Let yourself be guided by the feminine, right brain inspired ideas, and use your masculine aspect to act on them in this world. In the strength card, we see another woman taming a beast, so, one woman looking to heaven, guiding a man and the other guiding/taming a beast, looking to earth….both the sacred and profane each holding a key in guiding ourselves toward that which we love.
On a more mundane, divinatory level, I have seen this combination as a strong relationship, or teamwork, tacit agreements between people. Strength in some decks is sometimes called “lust,” so if you’re doing a relationship spread, then good sexual chemistry is a possibility, or a love affair with that “beauty and the beast” kind of quality.