高端大气你石姐
[gāo duān dà qì nĭ shí jiĕ]
In colloquial language this roughly translates to 'High Class You Big Talker.' There's humorously sarcastic use calling the person 'older sister' - typically signifying affection mixed with tease- alongside pointing out grand airs without basis ('big talk'). It’s likely poking fun at someone who exaggerates their importance/status but keeps tone casual among familiar people.