The nose/bumper moulding is the obvious brand focus, and the Aygo's has a more conventional face than those of its open-mouthed cousins. It is also the most modern looking of the triumvirate.
The Toyota also eschews the scope for minimalism at the rear corners, rather than embracing it as the PSA cars do.
It has a separate rear-quarter body panel between a conventional door-shut line and the tailgate, whereas the five-door C1 and 107's rear doors include the wheelarch and extend right up to the vertical, wraparound tail lights so there's no external quarter panel at all.
Either way, these are very compact cars with an overall length of just 3.4 metres and almost no rear overhang. The deep rear window forms a one-piece tailgate in another clever piece of parts-count reduction.
That's important, but not only has the Aygo et al been conceived to be sold as a cheap car, it has also been designed to be cheap to repair too.