Icons and POIs are two different things

The icon is the image that is displayed on the nav.

On a Mk4 nav with current software the icon is a PNG file, 28x28 pixels, 32bit depth, size around 600 to 1000 bytes.

A POI list is a list of POIs with, as a minimum, the lat/long location and the POI name.

Try http://www.poiplaza.com/ for a source of POIs