Mood: The mood of the image is romantic and nostalgic, evoking a sense of love and reminiscence. The theme appears to be a musical compilation or a retrospective of popular songs from 2015, likely from the Indian music industry. The overall emotion is upbeat and celebratory, suggesting a collection of hit songs that people will enjoy.

Environment: The environment or setting of the video is likely a music compilation or a playlist, possibly featuring popular Bollywood songs from 2015. The setting may include a montage of various scenes, such as romantic moments, dance sequences, and other performances, set to the music of the featured songs.