5:22 looks like the sign has a very large white frame and now one can see through the right part of the sign that doesn’t go all the way to the vertical part of the frame.
https://m.youtube.com/watch?v=3PhC3UZLPxI
At 5:22 presently on the left we are either seeing through the right side of the black “sign” or it is showing us a reflection of what is to the right of it and closer to us.
https://m.youtube.com/watch?v=3PhC3UZLPxI