Often what you see on such photos are either members of German minorities living in the occupied country, or local Nazis/Fascist movements that ideologically had submitted to German Nazi dominance, often with the hope of being placed in powerful positions after the occupation.

The German minorities in Poland, Czechoslovakia, France, Denmark, Holland, Belgium, had been more or less slowly Nazified since the 1930's.

At first the German Foreign Ministry (AA) was leading the nazification, later the SS via VoMi, or similar "cultural aid" organisation, some of which pre-dated the Nazi takeover was the driving force. A powerful tool in controlling the German minorities was by taking over their cultural and political institutions, often via funding pro-nazi candidates and removing funding from those who opposed total nazification.

By and by, Nazi Germany thereby succeeded in nazification of the German minorities in its bordering countries.

Quite a few minority leaders thought they could use Nazi Germany to their advantage, but it was a devil's pact many came to regret; their communities suffered on the bloody battlefields, and postwar many were persecuted, killed or driven into exile from their homes because the Nazi regime had used them to commit atrocities in their own country.

A good English language entry into this nazification of European German minorities (though not dealing with the postwar period) is Valdis O. Lumans ; "Himmler's Auxiliaries".