Interesting demo. I'd argue that a good tutor will ask more questions than answer. The tutor has to gauge the learner's understanding and adapt instruction. Properly formulating a question can be tricky if you're confused.
Also, I asked some math questions, and the AI started talking about and giving equations. For me, at least, this was impossible to understand. I know part of the point of this is to make it conversational, but I would think having a transcript displayed somewhere would help a lot.
For bonus points you could do this with the voice input. Only show the transcription when it's relevant or if the user asks.