不明觉厉
bù míng jué lì
or another common way of putting this is to use this sentence:
"虽然不明白你在说什么，但感觉好厉害的样子"
"Suī rán bù míng bái nǐ zài shuō shénme, dàn gǎn jué hǎo lì hài de yang zi"
‘Even though I don’t really understand what you’re talking about, it still seems pretty amazing!’
This is a phrase most often used to express admiration towards users who are seen to be experts in a certain field. However, it may also be used in a mocking sense, implying that a person is simply putting on a show, and actually has no idea what they’re talking about either.