Mood: The mood of this video appears to be celebratory and appreciative, with a sense of achievement and gratitude. The theme seems to be centered around a milestone of 100 million subscribers, indicating a significant accomplishment in the realm of digital media, likely a music channel given the ZEEMUSIC CO. logo.

Environment: The setting seems to be a digital or virtual environment, likely a YouTube channel or a similar platform, given the context of subscribers. The background, with its dark tone and specks of light, resembles a starry night sky or a festive atmosphere, often used in celebrations and achievements.