Indeed. It's not a true optical illusion or deliberate trick photography. It's us reading the picture wrongly.
Usually when you re-examine, there's some other context detail you've overlooked. Such as there's one less tooth between the previous letter and the one you're looking at, than on the real thing.
You have to check, double check and triple check.
The 1909 one is difficult, as depending on how you look at it, the base of the one can be over a tooth or over a gap. Although on the real deal, there seems to be a marginally larger space between teeth, and the base of the one is literally smack over the tooth. I would say with that one, unless it's absolutely obvious at first glance under magnification, then it isn't a 169. The hollow neck is really difficult though, IMO.