Settings

Everything is set in Settings… (a few also in the menu) and in the config file; either applies straight away. A new install shuffles every style and tonality, shows one picture on every space, and draws a vignette and a subtle grain.

Setting	Default	Settings page	Config file
Style	Shuffle among all	Picture	`[style] mode`, `always`, `never`
Tonality	Shuffle among all	Picture	`[tonality] mode` (shuffle, season, always), `always`, `never`, `hemisphere`
Vignette	On, 1	Effects	`[effects.vignette]`
Grain	On, 0.035	Effects	`[effects.grain]`
Dither, halftone, glass, bloom, light leak, paper, posterize	Off	Effects	`[effects.<name>]`
A random effect on each shuffle	Off	Effects	`[effects] random`, `random_never`
Shuffle	Never	Schedule	`[shuffle] every`: never, hourly, 3h, daily
Shuffle on login and wake	Off	Schedule	`[shuffle] on_wake`
Spaces	The same picture everywhere	Screen	`[screen] spaces`: same, different
Hide the notch	Off	Screen (and the menu)	`[screen] hide_notch`
Round corners	Off	Screen (and the menu)	`[screen] round_corners`
Title	Off; `{computer}` over `{user} · macOS {os}`	Title	`[title] show`, `title`, `subtitle`
Lock screen motion	Off	Lock Screen Motion	`[motion] lock_screen`
Motion speed, movement, settle, easing	Normal, normal, 2.5 s, ease out	Lock Screen Motion	`[motion] speed`, `movement`, `settle`, `easing`
Open at login	On (turned on once, when Undertone first runs)	General	not in the file
Pause	Off	the menu	not in the file

What is showing now, the time of the last shuffle and Pause live in Undertone's own preferences (io.github.mpdreamz.undertone), so a shuffle or a pause never changes the config file.