I am a Journeyman Glazier that has installed upwards of 4000 frameless showers. I am not keen on this lay-out for a number of reasons.
A) you don't need u-channel. It's a "cheat" and means someone didn't want to take the time to measure and silicone properly. It gets grimy fast.
B) the safest and most stable place for a door is ALWAYS hinged on the wall. If it must go glass to glass or in a corner, I would have preferred to have seen more support at the top. They could have run the glass up to the ceiling, or used a small chrome support bar to the ceiling. I do note there is a top corner clamp which is the minimal solution.