We have other images of this German falconer with a golden eagle, here he is shown with a goshawk. The second image is the writing on the reverse of this picture and has not been translated.
With thanks to friends Albert Raimund Gattung
and Regine Gattung-Petith the following translation has been given,
In German : "2 treue Freunde bei der edlen Jagd"
In English "2 fast friends nobel hunting".
If anyone has any other information