People, together, interact depending on informal "group rules" that modifies slightly each member's own personality.
People alone are themselves: they can be happy, sad, lost in their thoughts, crying, laughing, without anybody to question, blame or judge them.
Sometimes I must admit I feel like a voyeur when I make these kinds of shots.
But finally, they are just true lives shots.
Young lives, old lives, happy lives, sad lives, poor lives, rich lives (i'm not talking about money when I think "rich" and "poor"), loveless lives and...lonely lives.
We're all alone until we find love.
And love is not eternal.