For quite some time the forum UI looks different at different times on my iPad. Today it changed within minutes and I was finally smart enough to capture them both:
I’ve seen this on and off since I got the 2018 12.9” iPad (so for a few years.) Not every Discourse forum does it, but at least a couple do. https://meta.discourse.org/ would be interested but I think they’d want more information than just screenshots.
It could be because at some point (either first load or after) the iPad gets rotated to portrait view. That switches into mobile view and perhaps it isn’t switching back when you reorient to landscape.
IMHO fig is not bad per se, but is pretty unnecessary given discourses front end capabilities when using an iPad (i dont’ do forums while out and about). Only thing to adjust is the font size in Safari.