I recently got some (plastic 😬) bottles for home.
Not proud of it. But anyway, I noticed a small design anomaly with them.
Normally, the neck of most bottles are only slightly shorter than their lids.
Now while these bottles are fine otherwise (except, plastic!), I wonder how many people who’ve bought them have unintentionally spilled water on themselves while drinking.
When we reach out for a bottle, we unconsciously gauge the height of the neck (also the mouth diameter), and the brain magically calculates an approximate “how much to tilt”…
But with these bottles, that seems a little misleading. You expect a taller neck than the lid hides, which means water will be out at a smaller angle of tilt than one expects.
Ideally, always either match or exceed (i.e. err on the safer side of) user perception.
This bottle’s neck design is like having a negative margin of safety.
Say a product has a 100 kg payload limit. It is designed with a margin of safety, meaning it will deform or buckle above 100 kg (maybe at 110, or at 120 or even higher), not exactly at 100. But then imagine another similar product with the same 100 kg payload claim, but one that buckles at 95.
This bottle neck is that. Not always desirable.