The K1 originally didn't come with special badging, aside from a single K1 badge on the boot lid.
Per your link Cupra, 14 years later, decided to offer some numbered badges to officially mark it as a limited edition - it wasn't originally - but owners had to apply for them.
Which the car in the pictures lacks as well as the usual Cupra text, so indeed either not a K1 but a replica or a modified one. Probably modified as the descripton says "Also benefits from: H&R lowering springs, H&R spacer kit, Small front number plate, custom candy red painted brake callipers" but in any case not fully representative of a stock K1 version.
Finding an image of a bone-stock example is not a particular concern in this subforum. Never mind the fact that the only visual difference - given that it has the model-specific body kit and centre-exit exhaust - is a K1 badge and the CUPRA wordmark lettering.