Nice picture of line mechanics standing at front of Potez XXV . Picture taken around 1929-1931. As inscription from the reverse side indicates, this particular Potez belonged to 35 Polish Squadron, so possibly the picteure was taken at Poznań Ławica.
The propeller – most likely – is Plage Laśkiewicz one, made of ash plys, covered by transparent varnish, without decals. (entry: 1921)