When Tom heads back towards the bookshelf with the green stilts to go after Jerry, the bookcase is empty again. Then in other shots with the bookcase, some items are back on the shelves and some are missing. When Tom comes back inside after flushing Jerry out with the hose, everything is back on the shelves of the bookcase. Then later on when Tom chases Jerry back into the bedroom after he returns, the bookcase is empty again.