How may i install stuff into the live environment?

it installs, but doesn’t work. See Can pacman update just the pertinent packages?

Yesterday once booted into manjaro-kde-21.1.6-minimal-211017-linux54.iso live one of the first things i did is launch a Konsole. And again today. Yesterday i’d stretched it horizontally even wider than my first two screens. But, today it came up already wider than my first two screens! Whoa, Nellie! How did it remember that? Where did it store anything? Or perhaps it’s because my 3rd screen is wider, and maybe my 3rd screen was off yesterday, and today it’s width was considered as Konsole came up, even tho the Konsole window got placed on the 2nd screen?

One of the things i did yesterday was

mkdir /a2
mount /{dev/sd,}a2
mount -orw,remount /a2

so did /dev/loopN maybe write stuff right into the .iso? The .iso still passes sha256sum -c so it couldn’t have. TAIA