Oddly, I've noticed that reference to "gum chewing" americans a lot. Never understood why, but the germans in WW2 looked down on "gum chewing" xD
The americans probably sneaked into German barracks at night and stuck gum under tables and into sleeping soldiers hair.
British soldiers take cover from German shelling in a shallow trench during the breakout. The trench is similar to many which were dug along the opposing front lines during the lifetime of the bridgehead.