If the title was "spot glossed" then parts of the title would be glossed and other parts of the title would be matte.
That's what "spot" means in this context. Like "spot checked" or "spot cleaned". Some areas are checked but not all. Some areas are cleaned but not all.
SteelBooks can be "spot glossed" meaning parts of the SteelBook are glossed but not all.
So is the title really "spot glossed?" Are only parts of the title "Jungle Cruise" glossed while other parts of the title are matte? No. Therefore the title "Jungle Cruise" on the front of the SteelBook is "fully glossed".