"The Burning Court" | I have created a "floor plan" of the crime scene

Based on the original work by John Dickson Carr
The brilliant and fantastic mystery novel that shines in the history of the genre, "The Burning Court"

What kind of room was the victim spending time in?

As those who have read it will know, it is difficult to grasp the image of the crime scene room!
I have seen many opinions online saying that "it would be easier to understand if there were a floor plan," and I searched for one myself, but could not find any.
So, I created a floor plan in my own way. (I hope this will be helpful for those who read it in the future.)

First, the usual state of the room.

★Spoiler Alert★ How did the room change that night?

Next, the state of the room at the time of the crime.
This is the famous trick where "a person passes through a wall and disappears."

★The circled numbers in the diagrams correspond to the numbered points in the explanation text.

① First, the victim (Miles Despard) moved the desk with the mirror on it to the wall on the opposite side of the room.

• At this time, he hung the Cruise painting on the door leading to the nurse's room.

• Also, the high-backed chair was placed against the door of the nurse's room (to prevent unexpected entry) as a prop.

• Whether these tasks were done on the night of the incident or before that is unknown; the specific date and time are unclear.

② On the night of the incident, the witness (Mrs. Henderson) is peeking into the victim's room through the curtains from the glass door at the end of the sun porch.

③ The culprit makes the victim drink the arsenic-laced beverage. After finishing the crime, they walk toward the nurse's room. *Note: At this stage, they have not yet entered the nurse's room.

(4) The culprit's figure gradually appears in the mirror on the desk. (To be precise, is it an image of the culprit appearing in the mirror with the "door leading to the nurse's room" and the "Cruikshank painting" as the background?)
Depending on how the "chair" is placed as a prop, it is thought that it would not be reflected in the mirror.

(5) The image mentioned in (4) above (the culprit with the door and the Cruikshank painting in the background) emerges in the witness's line of sight.
Since only the light by the bed is on (the light illuminating the wall is off), the witness does not know that the person they are seeing is an image in the mirror on the desk.

(6) The culprit enters the nurse's room.

(7) To the witness, it appeared as if the person in their line of sight (the behavior in 6) had walked out through a door that shouldn't have been there.

(8) The victim later returned the desk, the Cruikshank painting, and other items to their original positions. (Because they performed such heavy labor while arsenic was in their system, they began to suffer immediately afterward.)

Am I the only one who feels a bit uneasy about this?

I don't intend to criticize the novel, but there are some points that I just can't quite accept.

• In the novel, this mirror is described as a "mirror on the desk."
  I imagined a "small mirror sitting on a desk," and I feel like that would only show, at most, a face and perhaps a bit of the shoulders.
  However, based on the witness's testimony that "the person walked out of the door," perhaps the original author, J.D. Carr, wrote this while imagining something like a dresser.

• If the witness was surprised that "a person walked out of a door," they surely would have doubted their own eyes and stared even more intently at where they were looking.
  Even if it was dark, they should have noticed the existence of the mirror.

• Since this trick relies heavily on the victim's prior actions (1: moving the mirror), it seems like a very convenient situation for a trick.
  On top of that, the victim's own actions (8: returning the mirror to its original position) erase the evidence of the trick.
  In the first place, the culprit's goal was to frame a third party by committing the crime while in costume (the costume of Madame de Montespan, a favorite of Louis XIV).
  Therefore, it can be said that this trick created a byproduct situation for the culprit. (Perhaps the culprit didn't even realize the mirror was there to begin with?)

• As the story progresses, the room (the crime scene) is described many times, but I was surprised when the word "mirror" suddenly popped up for the first time during the explanation of the trick in the final stages.
  I felt like, isn't that a bit unfair?

Why is the public so indifferent to this trick?

This mirror trick is surprisingly rarely discussed online. (Are most readers not very interested? Was it impossible to understand in the first place? Or is it considered not worth explaining?)

I got the impression that public opinion is mostly focused on the fantastic atmosphere that permeates the entire novel and the eerie scene in the epilogue (the core of the incident).