What’s the benefit of placing speakers like this? (diagonally at the corner)


I am curious about the speaker placement.
(I try to upload a picture.... not working well...)

Here’s the link to Positive-feedback website containing the photo of speakers.


Let’s say this is the corner of the square shape room.

| [amp]
| (Empty) (Empty) [Sp2]
| [Sp 1]

(Facing toward the other side of corner)

Amp is placed at the corner of the room. (Diagonally)

Then Speaker 1 (Sp1) and Speaker 2 (Sp2) are placed diagonally too.

Amp and speakers face toward the other corner of the room.

I think this this is V.Rossi’s Audio show room picture from 2019 with QLN prestige 3 speakers.

What is the benefit of this kind of placement?
I use this setup in my listening room.  Did it mostly for interior design benefits given my furniture, windows, fireplace, but things sound spacious and echo free.  https://systems.audiogon.com/systems/9074
I think  my current listening space in my hexagonal shaped bedroom has pretty much the same effect as the setup in the Vinnie Rossi article. I chose to treat the 1st order reflection coming from a short wall next to my left speaker, but otherwise the room seems to naturally sound great. Compared to the square or rectangular rooms that I've previously had, this room sounds exceptionally quiet. I can that tell there are few if any stray reverberations mainly because I don't hear the echoes that I just unconsciously thought were present in all rooms.
The primary reason is much smoother bass as the standing waves are not allowed to multiply as much as in a rectangular or square room.
Jim Smith
Echoing Redwood set up a pair of Celestion 600s that way in living room 30 years ago looking to save space and accidentally discovered the added benefits of clearer and cleaner sound on the whole. Speakers in rectangular rooms sounded muddy even when separated from all walls so I would assume the mid bass was tamed in this configuration avoiding sidewall reflections. Soundstage depth also benefitted. 
"...Sanders set up their ESL's at shows diagonally..."

And well out from any walls. They had the best sound at The Show.