When you buy all sorts of junk food stinking with bad fat, cholesterol and all those things you crave but which your badass doctor would advise against and put them at the bottom of the shopping bag and then cover them with a handful of fruits and vagetables.
It can also be applied to any other situations in which you buy something you are not very proud of, put it at the bottom of the shopping bag and then cover it with other items you are very proud to show off.
Derived from combining "shop" and "conceal"
Chloe shopceals to avoid her flatmates comments
You can't leave with that pack of codoms popping out of your bag, dude. Better do some shopcealing.