The Sketup 8 doesn't have the ability / option to create a reflecting surface. In this matter, you first need to export your project in V-Ray and add the reflection effect from there. To do this, you need to select the surface that you want to project reflection from, and under Edit menu, you will be able to find the reflection option. In this matter,I suggest that you use Google or Youtube to find a tutorial video or a walkthrough that can provide for the exact steps that you need to follow to accomplish this.
