They're referring to the cistern AFAICT - so they mean that the water storage cistern has a ceramic lid, the lid of the toilet bowl is likely wood, resin, or such.

TBH I can't see why with a close coupled toilet anything other than the bowl needs to be heavy ceramic.

Oh, the cistern? those are usually enclosed in the wall here, entirely invisible, without any lid at all.

Then how do you do toilet maintenance?

you open the wall. You can remove the tiles from the drywall surrounding the cistern.

Ok, as an American I have to say I marvel at the toilet technology in other countries. For example you guys often have two buttons on your toilets -- a #1 and a #2 button. It just makes sense.

What are the lids made out of then?

Typical toilets here look like this (before/after): https://www.bauen.de/media/media/Ratgeber/Ausbauen/Bad/Vorwa...

I see.. you mean tanks that are enclosed in a wall. This supports the theory that heavy lids on unenclosed tanks help with noise suppression.

OMG I just realized that may be why the author experienced temporary hearing loss! The lids are designed to capture and reflect noise back into the tank water!!

(Sorry, a little too excited about toilet lids today.)

You can buy a toilet with two buttons in the US as well. Home Depot's web site says they have 17 of one model of them in stock at the store near me.

Yeah.. and yet most of us buy the Ferguson.[1]

[1] https://www.youtube.com/watch?v=IL2YRDzpTL4

Not only that, but you see them in public places in the US also. Usually not in stalls, but in single toilet bathrooms.