Mood: The mood of the video appears to be romantic and celebratory, with a focus on love and relationships. The theme seems to be centered around Valentine's Day, given the title 'Valentine Mashup 2018'. The overall emotion evoked is one of joy, affection, and togetherness.

Environment: The setting of the video seems to be a collection of romantic moments, possibly from various movies or music videos. The images depict couples in intimate and affectionate settings, with a mix of indoor and outdoor locations. The environment appears to be lively and vibrant, with a sense of festivity and celebration.