They do more than that. If you ask for ui with a button that button won't be upside down even if you didn't specify its orientation. Lots of the detail can be inferred from general human preferences, which are present in the LLMs' training data. This extends way beyond CS stuff like details of algorithm implementations.
Isn't "not being upsidedown" just one of the default properties of a button in whatever GUI toolkit you are using? I'd be worried if an LLM _did_ start setting all the possible button properties.
Putting LLMs on a pedestal is very much in vogue these days.
If you ask for increase and decrease buttons they will put the right icons on it (not words) and lay them out right.
That’s exactly what they said. Details “elsewhere in its training set”.