LullbeeThe night light aisle is a wall of adorable glowing objects, and most of them are wrong for the job. The question that matters is not shape or brand, it is color and brightness, because light at night is not decoration, it is information sent to a body clock.
Warm beats cool
Bodies read cooler, bluer light as daytime information, it is the color of the sky. Warmer light toward amber and red carries the least of that daytime signal, which is why sleep-minded lighting has moved steadily toward the campfire end of the spectrum. As a simple rule, the more a night light resembles a tiny ember, the better. The more it resembles a phone screen or a cool-white bulb, the worse.
Dim beats bright, and none beats some
For the baby, the honest default is no night light at all. Babies are not born afraid of the dark, that fear typically arrives with imagination in the toddler years, and until it does, darkness is the better sleep environment. Most nursery night lights exist for the adult doing feeds and diaper changes, which is a legitimate need, met best by a dim warm lamp that points away from the crib and turns on only when needed, rather than a glow that runs all night.
Placement
Low and behind, never at crib eye-line. Light near the floor, away from the baby's sightline, gives an adult enough to navigate without giving the baby something to study. Pair the ember-light room with a deep warm track like this page's night drone and the nursery says one consistent thing, day is over.