It would appear that at some point in time the Tour lost its example question: it somehow has become ineligible and so has defaulted to the default unicorn example. Now, whilst the default is actually somewhat on topic for us it isn't a good example of a question we want to show new users so we should probably update it.
Last time this came up a list of questions was given to pick from. This list comes from this SEDE query of question that should be eligible to pick for the Tour that was shared on the main meta post asking what can be chosen for it.
So can we decide on a new question to show on the Tour page?