例えば、たばこをぷかぷか吸う先生が、たばこを吸う生徒に注意してもその注意は矛盾しているだろう。

、、。

For example, if a teacher who's puffing away at a cigarette tells a student not to smoke, that warning would be contradictory.

Literal

For-example, cigarette [object-を] puffingly smoke teacher [subject-が], cigarette [object-を] smoke student [target-に] warn-[even-ても] that warning [topic-は] contradicting [conjecture-だろう].

A structured hypothetical argument. ぷかぷか is a 擬音語 mimetic for puffing on a cigarette or pipe — the soft, repetitive sound of smoke being puffed out. The sentence nests two relative clauses modifying 先生 and 生徒 (a smoking teacher, a smoking student). The pattern ~ても ('even if') introduces the hypothetical scenario, with だろう as the conjectural conclusion.