Squircled as in iOS, but not really covering the square, for example 256x256. At the moment it is ~82%, which is somewhat less useful. The squircle should take up as much as possible space within the 256x256 square. There is a loss of ~13% in height/width ratio.
The Desktop is not placed in a squircle, for there’s no desktop as such. As it can be seen, that square in the ‘squircle’ is not exactly square, so it is not a squircle, but a
rectangle-cle, flatter on the horizontal. If the squircle was a
square-cle, then the Trash icon, for example would look nice (consistent) on the dark Yaru theme.
Anyway, here’s how they look in the Menu,
They are not squares, so not squircles – not a square with rounded corners. Just rectangles with longer horizontal sides, or rectangle-cles. Note the round icons; the round icon touches the sides the 256x256 square exactly.
Below is an exactly square squircle icon. The folder image in it is still has the rectangle look.
And, this is the full icon, covering ~98% of the 256x256 square.
But, maybe having rectangle-cle icons are better for eyes, only the colours (at least for me) should be changed to something like cyan or teal.
Random non-squircled icons with somewhat lighter background, easy on the eyes.