Can anyone clear up what’s going on in this line:

Spoken:"Never say die; sways aboot non-chalantly pickin' his nails wi' 'is bayonet; an 'e
    knocks 'er off!..."

I feel like I’m missing a metaphor here that going to be obvious when someone explains it. Also, Just wanted to see if I could bring back a thread going since 1997 in 2019. Thanks!