The typed caption on this production still for the 1980 Bruce Beresford production of Breaker Morant seems to pretty much cover
what is going on film wise in the photo.  Personally Edward Woodward seems a bit bored (no pun intended) with the pictured
situation while Bryan Brown looks to be truly relishing gunning down the (off camera) attacking Boers.  

Black and White Production Still
10 Inches x 8 Inches (28cm x 18cm)
New World Pictures / Quartet Films
Australia
1980