LOONA TV #263 is the two-hundred-sixty-third episode of LOONA TV.
Chuu is filming a slowed down dance sequence for the "Heart Attack" music video while HaSeul, Kim Lip, and Yves watch from the sidelines. Kim Lip mimics the slowed down version of the "Are you ready?" line from "Heart Attack", and Yves replies, deadpan, "Yes." The members do a slow-motion version of the "X" move together. HaSeul explains that she stayed up all night before coming to the set today, but her turn to shoot isn't for several hours. Later, HaSeul changes into her outfit from the "The Carol" music video in preparation for her scene. She introduces herself as "Jo HaSeul, from London" and gives a quick rundown of her upcoming scene.
- Kim Lip's "Are you ready?" and Yves's "Yes." together became a meme.