嘟嘴卖萌做作
[dū zuĭ mài méng zuò zuò]
'Pout cutely and act', refers to intentionally acting babyish or silly, usually aiming to get others' affection, attention, or forgiveness. Someone using this as online handle might enjoy such playfulness, sees it as endearing trait in personality, maybe enjoys adopting playful or adorable image online.