The "<profile name>" and the "n" aren't marked as translatable. Attached patch adds the N_() macro.
Note that currently the style of the last 2 arguments is inconsistent with the previous ones:
-p, --profile=<profile name>
-w, --set-wallpaper=<image file>
Since you have no control on the --display=DISPLAY you may wnat to change the others to uppercase and remove the angle brackets.