What type of shower enclosure is sensible?

Thank you very much for your contributions

Main bathroom or guest shower?
What are the diamond-patterned surfaces in the shower?

No, it is not the main bathroom, but the toilet on the ground floor, where the shower is still located.
The diamond-patterned surfaces are partition walls housing the sanitary installations.

I also think 67 cm glass panel is enough ... however, I would not put a rain shower head in the middle of the shower area.

Hi

For a guest bathroom, I find a 60cm glass panel clearly sufficient.
What installations are necessary at the bottom edge of the shower in the picture?

Olli

Do not place a rain shower head in the middle of the shower area.

Well, the fittings are located on the upper wall in the plan. And the planned rain shower can be seen in the attachment.

What installations are necessary at the bottom edge of the picture in the shower?

Supply for the upper floor.

It also depends on the showering behavior how much splashes: when I shower, the water only splashes up to about 1.20 meters, with my husband almost the two available meters.
Something else: I would choose the sink one size smaller. A 60 cm one is a bit bulky, especially in a small bathroom.