深白色萌萌小忙内
[shēn bái sè méng méng xiăo máng nèi]
A blend of adorability ('moe') and cultural terms, where '深白色' could denote profound whiteness, suggesting purity or innocence, and '忙内' means the youngest member of a group. So, it refers to a cute and busy youngest member, probably from fandom contexts.