Mood: The mood of this video appears to be festive and energetic, with a focus on celebrating Diwali, the Hindu festival of lights. The theme seems to be a collection of popular songs from 2021, likely from Bollywood or Indian music. The emotion conveyed is one of excitement and joy, with the use of bright colors and lively imagery.

Environment: The setting of the video appears to be a vibrant and dynamic one, with a mix of urban and celebratory environments. The images suggest a cityscape or a party setting, with people dressed in stylish and festive attire. The presence of candles and decorative lights at the bottom of the image reinforces the Diwali theme.