One of the things that make K2 very powerful is the K2 plugin API, which is built on top of Joomla!'s plugin API. See more : http://getk2.org/
Using a K2 plugin you can easily extend the forms used for items, categories and user profiles. That means you can write a simple plugin to add additional fields and extend K2 forms beyond "extra fields". So you can write any plugin that brings programmatic logic inside the K2 item, category and user forms, which is by definition beyond the powers of any "CCK" system.
This plugin show a google map on items pages, the map is a fixe one create by a google account and the googlemap service, and the dynamique stuff are POI where the map is center onthe loading plugin.
So you create a map, add POI on it and you could have into the K2 item's back-end edition A postale adresse and the latitude & longitude for center the map.
Some css add for a responsive iframe ....