In photography, negative space — the area around the subject — does as much compositional work as the subject itself.
A portrait with the subject filling the frame reads as intimate or claustrophobic. The same subject with space to breathe reads as contemplative. The same subject with space they appear to be "entering" creates forward motion.
The mistake beginners make: they fill the frame because they think emptiness is waste. Negative space is not wasted; it's the context that makes the subject legible.