A nice touch is that the small size has a tighter knit around the edges.
Banksy Butterfly Girl Street Art T-shirt
What stands out about the small is its precise cut around the armholes.
American Beauty Album Cover Art T-shirt
You will notice the small size keeps the shirt from looking oversized.
Album Cover Art for Fly By Night T-shirt
You will notice the small size has a narrower chest panel for a snug feel.
Banksy Tank Graffiti Street Art T-shirt
The small size is a reliable choice for a clean, understated fit.