No. "Anonymous", is this sense, has a precise meaning. It does only not mean "we don't know the name of the author", it means that the author deliberately published the work without associating his name to the work. This cannot be changed even if the author is later identified, it is a choice made by the author.
On the other hand, simply not knowing who the author is does not make a work anonymous.
 

What is that supposed to mean ?
1) Does "pd" mean "public domain" here, for a start ? for what I know, it might be the initials of the photographer. The publication is in German, why would they say "Public domain" rather than "Gemeinfreiheit" ?
2) Assuming "PD" means "public domain", where does this image come from ? For what we know, it might well have been taken by a journalist of the newspaper, which is then entitled to releasing it in the public domain if they see it fit.
3) This image is not problematic. It is an original portrait of a person, and might well have an original value under Swiss law, or not. It is not a case where the person displays a Pokemon t-shirt as was the example.

Do you have precisions, or maybe another link ?
  -- Rama