When you insert the following in German Wikipedia
[[File:George w chadwick.jpg|thumb|George Chadwick]]
the following is displayed:
thumb|George Chadwick
This looks like a parser issue.
References:
https://de.wikipedia.org/w/index.php?title=Benutzer:FriedhelmW/Entwurf&oldid=159013077
https://de.wikipedia.org/w/index.php?title=George_Chadwick&oldid=145955966