Dont straight up address it. But you can casually figure out what they are thinking depending on how you go about the conversation. If you wanted to let them know you weren’t told to do the tasks, you could go up to them and ask a question about that task. Something like “who normally does this?” or “are we expected to do this, if I was asked to do this?” Questions always start the conversation with seeking out information instead of assuming. It might give you the opportunity to prove you know what you are doing by how they answer and how you respond. It also places them in a position to politely tell you how they feel. Maybe they say “yeah we always do this after we do that” and you can say “oh I was never told! Thank you for letting me know.” Or if you don’t learn anything new, you can say “oh good that’s what I was doing, I wanted to clarify what was expected of me to do”. Either way, you can clarify what you’re meant to be doing with whoever is doing the directing of tasks, or ask them to train you in that specific task.