The quiet request, written once and then done with
One line in the thread asking for little talk, no music or one lamp is read as an instruction rather than a mood, and it settles the room in advance.
It is a sentence, not a negotiation. Something on the order of: little conversation, no music, the lamp rather than the ceiling light. Written down, it arrives ahead of her and the room is already arranged in her head when she knocks.
Why writing it beats hinting at it
Without the line, the opening minutes of any visit go on two people working out how much talking is wanted, reading each other carefully and getting it slightly wrong in both directions. That is precisely the exchange a quiet guest booked in order to skip. Written down in advance it costs eight words and removes the whole of it.
It is not read as a mood
This is the worry that keeps guests from sending it, and it is unfounded. Asked for in the thread, it reads as a preference in the same register as the length or the hour. Asked for at the door, with a shrug, it reads as something being wrong. The difference is entirely the timing. It is a common enough request that no explanation is needed alongside it, and adding one usually makes it sound like an apology.
What it does not cover
It does not remove the short exchange at the start where she says where her limits are. That part belongs to her, it happens on every visit, and it is brief. Silence and little talk are also two separate requests, which the guide on silence, music or conversation takes apart properly, and the hub on booking with few words shows what a whole thread looks like when it is written this way.