In an official reply tweet by Rivian, the company stated some of the options presented on the glass panel on the model R1S.

R1T and R1S trucks are highly expected on the EV market and can definitely be a huge success when launched. One of the main reasons for that are the features available in them.

Confirming the removable roof, the tweet by the company also talked about electrochromic glass and a fixed glass panel. There are many options for the style of the roof.

Hi Steven! We will offer multiple roof styles including electrochromic glass (which turns from opaque to transparent on demand), a fixed glass panel, a two-piece removable composite roof and a standard fixed roof. — Rivian (@Rivian) August 13, 2019

The reply was made after the company posted a picture of its truck in the woods carrying a bicycle.