I find this very strange and I don't get the logic behind. Maybe you can shed some light on this.

Yes, I can.

The texture coordinates are not recognised when you use the first method ( left), so the texture is applied using the predefined size.
The other method will use the texture coordinates when you apply a texture, and give the texture a relative scale as described by the coordinates. Any texture , no matter the size, will be rescaled by the texture coordinates to fit the model.


You have to use this method to get the result on the right:

If you are changing texture you have to scale and maybe alter the x/y coordinates of your texture before you apply it to all six sides.

Cec