The answer is not as obvious as it seems at first glance. It depends on controlling gadget position, camera aspect ratio, and aspect ratio of your screen. Below we suggest a detailed analysis of some practical cases.
This is a companion discussion topic for the original entry at https://community.robotshop.com/blog/show/how-to-mount-a-tablet-in-the-telepresence-robot-head-horizontally-or-vertically-3