If there are 4-dimensional shapes in the universe, here you can see the 3-dimensional shadow of a cube. But notice that your screen is 2-dimensional. So you see the 3-dimensional shadow of a 4-dimensional shape in 2-dimensions on your 2-dimensional screen. So it is the shadow of the shadow.

You can see and study this theoretical hypercube on the internet on related sites.

https://en.wikipedia.org/wiki/Hypercube#If we were two-dimensional, we would only be able to see a two-dimensional shadow of a three-dimensional ball or sphere, which would be a circle. But we wouldn't be able to see the shadow of a 3-dimensional ball in the shape of a 2-dimensional circle. Now, because we are looking from the 3rd dimension, we can easily see the 2-dimensional circle shadow of the ball. But since 2D creatures cannot look from above, they will only see part of the shadow and not the rest. More precisely, they will see the shadow as a "convex line" and will not be able to perceive it fully, even in 2D...

To prevent this, they will make the shape "transparent" as we do in the hypercube. In this case, they will be able to see the shape (the 2-dimensional shadow) but they will have the impression that a convex and a concave line are intertwined and mixed with each other.

Moreover, they will not even be able to imagine the original 3-dimensional shape.

By the way, Kabah means "cube" in Arabic.

The shape of the Kaaba is reminiscent of a cube, even if it is not millimetric, it can be said to be a cube in terms of shape (it can also be said to be a rectangular prism).

And that's why some people want to make a connection between the Kaaba and the hypercube, but this is a bit of a forced mental gymnastics, especially by the spiritists.

Apart from this, I would like to present another observation.

In the two-dimensional world, no living being can escape or hide from three-dimensional beings. A two-dimensional being who thinks he is hiding inside his house and cannot see the 3D being can enter his house from above without any obstacles. Because there is no such thing as height in his 2-dimensional world, for example, he thinks that a wall in the shape of a circle is protecting him, but upwards he is completely defenseless.

Not only that. A higher dimensional being can see and touch the inside of your body, even the inside of your organs.

In the same way, if it were a 4-dimensional or more dimensional being, it would be able to find 3D beings everywhere and even interfere with its internal organs if it wanted to.

(My Turkish article translated with machine)

https://emre1974tr.blogspot.com/2011/07/dort-boyutlu-bir-sekil-hiperkup.html