Tian Tai boundless swimming pool hand-drawn

Quick answer：

Tian Tai refers to a skyscraper's rooftop, and a 'boundless swimming pool' is an infinity pool that appears to have no end. The term 'hand-drawn' indicates that the image is a sketch or illustration created by hand. It could refer to an artistic representation of an infinity pool on the rooftop of a skyscraper, depicted in a sketch form.