Why it worked
The video taps into the popular trend of "aestheticizing" everyday items, particularly water bottles, to encourage hydration. The visually appealing glitter and bright colors make the mundane act of drinking water more engaging and shareable.
Summary
The creator is making their water more appealing by adding glittery pink liquid to a green Stanley cup filled with ice. They then put the lid on and take a sip, implying this makes them more likely to drink water.