It’s from Kight Scoop which takes requests from viewers. This episode was aired in 2020 that a girl requested to date Godzilla bcs she deeply, romantically loves Godzilla. I haven’t seen it but it seems this clip is the end of the date she proposing him.
Japanese use JIS but A size is the same with ISO so there’s no confusion here. For B size there’s slight difference in JIS and ISO, but as end user I hardly print anything other than A4 so haven’t encountered problems myself.