They're .desktop files! Essentially like shortcuts in Windows. So I can set the name and icon to be whatever I want them to be, as well as passing in extra parameters to Decker when I open it (so I can have them always open fullscreen). The actual .deck files live elsewhere.
So for example for the links to my zine I might have a file named issue1.desktop that contains this
[Desktop Entry] Name=zine of millie, issue 1 Exec=decker --fullscreen "/home/milliesquilly/kioskfiles/zine/s1/zine of millie issue 1.deck" Comment= Terminal=false Icon=/home/milliesquilly/kioskfiles/icons/zine.png Type=Application Name[en_AU]=zine of millie, issue 1