TinyURL? what is all this about?

The full tinyurl given in the error tile is http://tinyurl.com/osmtile1. It redirects to the following mailing list message:

http://lists.openstreetmap.org/pipermail/announce/2012-June/000062.html

The mail announces a change to the URL formats recognized by the OSM tile server. Probably you are using one of the disabled URL syntax variants to access Mapnik tiles. Use the valid URL format described in the mail instead:

The only valid URL format is: http://tile.openstreetmap.org/{z}/{x}/{y}.png

Valid host aliases are: a.tile.openstreetmap.org, b.tile.openstreetmap.org, c.tile.openstreetmap.org, tile.osm.org, a.tile.osm.org, b.tile.osm.org and c.tile.osm.org

Other variants do no longer work. But instead of just rejecting those old variants, the server has been configured to return tiles with an embedded error message such as this one (which is presumably what you are seeing):

The idea is to give those who have not yet updated their websites and applications a chance to learn about the change and the necessary steps to get the tiles working correctly again by following the URL given there.

By the way, the black-and-white pattern is a QR Code. It represents the same link as above in a format that can be read by mobile devices with cameras.