Overview
Moominized character speaks that character's lines with a close-up in the second panel (ムーミン化したキャラにそのキャラのセリフ喋らせて2コマ目でア, Mūmin ka shi ta kyara ni sono kyara no serifu shabera se te ni koma-me de a) is a short-hand notation for Moominized character speaks that character's lines with a close-up in the second panel, it usually works out cartoonishly, a Japanese meme.
For more details refer to the article Moominized Character Speaking Their Line.
Related Articles
Moomin Moomintroll Twitter Parody Drawing Parody