The ethics of power dynamics… what would you do?

I would like to think where the meeting was scheduled in advance, the room would have been set accordingly with glasses and water on the table for attendees to help themselves. It is often the case to delegate 'lower value' tasks down the chain of command so to speak and this is what has happened in this situation. Our office is a good example. We have administration staff, skilled staff and senior staff. It is the expectation that the administration level staff will prepare our meeting room including water for clients prior to each meeting. On occasions where no admin staff are available then it becomes the responsibility of the person hosting the meeting or anyone else who notices the room is not ready for the upcoming client meeting prepare it as necessary.
The request positioned here could be taken two ways. Either as an arrogant abuse of power or a polite request. It is difficult to know how the request was intended but perhaps could have been avoided with preparing the room for the meeting by an administrative level staff member.

Respectfully, since the youngest team member is the person presenting, it is not appropriate to ask them and disrupt the meeting.

If I was in the meeting observing this I would immediately get up and offer to get the water myself allowing the presenters to continue. This act demonstrates to the other senior leader what servant leadership looks like in action. If I was challenged during this action, I would insist and then offer my reason why, saying, it isn't appropriate to ask "xyz" to get water etc..thereby firstly demonstrating behaviour by action, then if necessary by using words if the action wasn't clear enough and doesn't sink in.

If I felt uncomfortable I would offer to help. After the meeting I would bring it up with my colleague and remind them that our actions demonstrate the culture. What message is that sending to our colleagues but importantly to a young person in the organisation.
If there was a gender imbalance in the room and the person being asked was a female I think I would say, "please don't, you prepare for your presentation and I'll get the water"
Too often I have stood up from a meeting with mostly men and they have all left the room without clearing their glasses etc.