How to texture LOD model versions?

In the unity docs here: http://docs.unity3d.com/Documentation/Manual/LevelOfDetail.html it shows in the screenshots that the hipoly and low poly meshes are both only using one material. How can you texture the low poly like the hipoly without having the geometry anymore? One large texture? That doesnt seem very optimized? And the hipoly only has one material also. That too seems unoptimised since the thing to do is break up parts that tile, like brick, and then have separate texture for window, etc. Feels like im missing something with how everything got textured...