Service interval reading

Hi all,

I'm considering buying a C4GP 17 plate, Petrol Auto 1.2

It had its first service after just over 12 months and at 19k miles. From what I can find on here, the service interval should have been 16k - so it's a little late. Can anyone confirm the service interval?

Also, the service indicator on the car is now saying 6 months or 8k miles until next service - which seems a lot shorter than expected...although will depend on future use of course.

Seems strange that it's saying 8k miles until next service, but is there a reasonable explanation that I'm missing?

Any advice tips welcome. Thanks.