Mood: The mood of the image appears to be melancholic and introspective, suggesting a theme of regret or longing. The title 'REGRET' and the achievement of '1+ MILLION VIEWS' implies a sense of impact or resonance.

Environment: The environment/setting of the image is unclear, but the background of the photos appears to be an outdoor or urban setting with a blurred or indistinct background, focusing attention on the individuals. The overall aesthetic is muted and subdued.