。
She talks like she knows everything.
Literal
[topic-は] just-as everything is-knowing-[such-as-ような] speaking-style [copula-だ].
話しぶり ('manner of speaking, way of talking') parallels 顔つき (face-look) and 口ぶり (speech-tone) — concrete nouns describing the observable cast of an action or feature. 何もかも ('everything, every last thing') intensifies the more neutral 何でも by emphasizing exhaustion of categories: literally 'what-also what-also.' The simile frame まるで~ような modifying 話しぶり gives 'a way of talking like [she knows everything]' — a thinly veiled critique of someone speaking with unwarranted authority. The implied complaint matches the English 'know-it-all' attitude.