The third sign of the western Zodiac, Gemini the “twins”, first brings to mind some notion of duality. But it is also a symbol of replication and variety. This sign is “mutable” in quality. Aries as a “Cardinal” sign belongs to a group that is guarded and cautious (although Aries has its moments of impulsiveness, ironically). Taurus is part of the “Fixed” group of very decisive black or white extremists. “Mutable” signs like Gemini are curious, sometimes highly intellectual, of broad and varying tastes and interests, and very indecisive. This is because to Gemini, variety kills their worst enemy, boredom.
So Gemini is typically all over the place, in mind, opinion, and even direction. Obviously, a sun-Gemini with six planets in Taurus will be more firm and solid. And another with a strong Cancer influence will be more cautious and guarded. But a very Gemini personality is usually outgoing and highly talkative, and values great “conversation”, a gift of the planet Mercury, a celestial body connected to communication, languages, information, education, technology and travel. So many individuals with prominent Gemini planets in their charts have a knack for languages, make good reporters or simply love engaging in idle gossip. Some Gemini folks travel a lot and relocate to another city or country at some point in their lives.
As typical with the Mutable group, they can sometimes appear nervous and even hyperactive, or at least very energetic. Gemini has to be careful not overwork their nervous system. The parts of the body associated with Gemini are the lungs, arms, hands and fingers.
Many of them have a knack for some creative skill, like writing, painting, singing or acting. I've known a few who incorporate images of hands into their artwork.They dress and decorate environments with vivid colors and bold, contrasting patterns with intricate details that demonstrate the "handiwork" of the artisan. So hand-made things really appeal to their eclectic tastes.
When I made the t-shirt, I wanted to incorporate the third sign's connection to early childhood, when children are best skilled at learning languages and speech in general. Gemini is associated with brothers. So I thought brother and sister was appropriate.