the way to do that i would have thought is as follows.
set an additive (i.e Vegi for example) , tick the now available “vegi” additive in the appropriate menu item and add some css image to the relevant elemnt ie
wppizza-loop-additive-x{/your image/}
‘x’ being the additive id
does that help
PS currently the additives in the loop are id’s – which is wrong, they should be classes – I will fix that in the next update