The What Is Love? Monograph is a limited-edition companion to TWICE's 5th Mini Album, released September 10, 2018 (delayed from its original August 31 date). It features a 150-page photobook with exclusive behind-the-scenes photos from the album jacket shoot and "What Is Love?" music video production, along with 9 individual member photocards. This monograph marks a significant shift in the series — it is the first TWICE monograph to not include a DVD, a change that carried forward for all subsequent monographs. For collectors building a complete monograph set, this is the transitional piece between the DVD-era and photobook-only era of TWICE monographs.