Most wallpaper shops pre-crop to a single phone shape, locking you out of the composition. We compose in 4:5 — the cinematic frame used in galleries and on film — for three reasons:
You choose the crop. iPhone and Galaxy let you pinch and drag when setting a wallpaper. The 4:5 frame gives you breathing room on the left and right so you can put the subject exactly where you want it — above or below the clock, centred or offset.
iOS Depth Effect works better. Apple's Depth Effect layers the clock behind your subject. It needs visual room around the subject to do this gracefully. Tight 9:16 crops fight Depth Effect; 4:5 gives it space to work.
One file, every device. Your 4:5 wallpaper fits your iPhone, your Galaxy, your Fold (where the unfolded inner screen is almost exactly 4:5 rotated), and your tablet — all from a single purchase. No re-buying for every screen.