This one turns out to be unique - not a lot of people can just get on it and ride it away. But there are sometimes other motives.
Trek also made a neat version of one of their city commuter steel framed bikes for Colleen in an extra tall size with a 70 cm frame. Something like 1 in 10,000 guys have legs long enough for it and only a tiny number of women. It is possible and even likely that she is the only woman in the world that this ride exactly fits. But while someone just riding away on it isn't an issue, there is always the problem of someone stealing it for parts.
If you are interested in the design and manufacture of objects that are to be used by people, it is sometimes very useful to look at folks on the extreme ends of the user spectrum to see specifically what breaks. Compromises are made in design as well as manufacture that limits the population - size, weight, dexterity requirements, cognitive issues and so on. It can be a fascinating exercise to see how standards came about and just where they break. But people who are outliers in one way or another frequently have to suffer with something that is ill-suited or just not be able to use something at all. Sometimes it is possible to make something custom crafted for them - sometimes by scaling a design and sometimes entirely new design is required.
Custom bike frames can be expensive and those that are unusually sized can require some serious engineering. Most people can be accommodated with stock frame sizes, but getting a bike fitted is a very important step and a good reason for trading with a competent bike shop rather than a big box store.
Of course sometimes a person wants a once in a lifetime bike that fits perfectly and can drop the money for a bespoke bike frame. Some are pretty amazing . The cost of a bespoke frame can be expensive as far as bikes go, but when one considers the hours of work and expertise required to make one they can be relative bargains.
But beyond bikes - this need to think more deeply about fitting the extremes among us is important and I wonder if advances in manufacturing will be supported by a greater facility with design. I'm inclined to be somewhat doubtful as design and engineering for small numbers is very expensive and frequently non-trivial.