Why it worked
The video likely performed well due to the combination of popular characters (Disney), a relaxing and visually satisfying activity (coloring), and the ASMR aspect of marker sounds. The use of bright colors and the transformation from numbered outlines to a finished image are inherently engaging.
Summary
The video shows a person coloring in a Disney "Les Grands Classiques" coloring book. The creator uses various markers to fill in the numbered sections of a character illustration, following a color key. The process is shown in a time-lapse style with close-ups of the coloring.