OIC , yes I can see that. The background in yours is coincident too..unlike the author's background..
With my eyes being cross-eyed -- the model is in front, with the ball between her and the model's name which is far behind both. Thanks for your explanations. 👍😊

I was just editing my post and someone (probably you) did something and it all vanished because only one post can be being edited.

So to write it a second time , I repacked a new version of the scene here:
https://bit.ly/3BFPklI

In the shader .fsh file the following can be edited:

// Define the interocular distance (adjust this value as needed)
float interocularDistance = 0.04; // Positive value for demonstration

Increasing the interocularDistance will make the background move further back.

In the scn file this section controls the model and her magical floating disc:

// LHS Scene
node{
node{
node{
node{
pos: -1200, -100, -1000

Pushing this to the left say changing -1200 to -1250 will also push the model further back.

I find them a bit temperamental. I find the depth of the model needs to be not too different to the background to get a good result.

Sure.. I was editing to say.., 'yes I can see that would be the case for peeps with a headset.'
Tks for your link in shadertoy. Will be helpful to others as well.
I might stick to doing 2D conversions more for now. lol.