Adding PNG-WEBP-KTX information

Added information to the readme about the texture format decisions.

Models/SunglassesKhronos/README.body.md

@@ -89,6 +89,12 @@ This asset uses only one texture, for the Khronos Group logos on the black earho
 ![The PNG texture used by the glTF asset](screenshot/SunglassesKhronos.png)
 <br/>_The SunglassesKhronos.png texture._
 
+[PNG](http://www.libpng.org/pub/png/spec/1.2/PNG-Contents.html) was chosen as the initial texture format because the image contains mostly larger areas of flat colors, which is ideal for PNG compression. The glTF Sample Assets repository aims to reduce or eliminate compression artifacts in assets, to provide the highest quality content with the widest compatibility.
+
+[WEBP](https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Vendor/EXT_texture_webp/README.md) was chosen for the compressed version because small file sizes are essential for many e-commerce assets, which reduces the download time for consumers. The longer users have to wait for a file to download, the more likely they are to abandon a 3D experience.
+
+[KTX](https://www.khronos.org/ktx/) was not chosen for texture compression because WEBP produces smaller files at comparable quality. KTX works well for applications where video memory is a constraint, for example when multiple models are being loaded together in a room planner and video memory is limited on a mobile device. Another strong use case for KTX is when GPU loading time needs to be optimized, for example when loading/unloading assets dynamically as in a product configurator.
+
 
 ## Iridescence