The term "shopped" means many things to many people. In general and at the very least it means cleaning the playfield, rubbering it, and replacing burned out lights. The game is basically playable, but may still have a few problems.
A more advanced "shopping" job would include repairing/adjusting switches, replacing failing/burnt GI connectors, recapping the power supply board(s), rebuilding the flippers, touching up playfield/cabinet artwork, installing remote battery holder for cpu board, etc.