What’s the explanation for the Martian look at z≤8? e.g. https://www.openstreetmap.org/#map=8/40/-111&layers=P https://www.openstreetmap.org/#map=8/40/-111&lay

What’s the explanation for the Martian look at z≤8? e.g. https://www.openstreetmap.org/#map=8/40/-111&layers=P https://www.openstreetmap.org/#map=8/40/-111&layers=P And it looks like this is a proprietary fork of Carto? Its inclusion on the OSM website is essentially an advertisement?