Can't get the pinting back issue at the retail store

Hi, I opened a retail shop in Magnolia and earned good money from selling my sims' paintings. This was good but I got a problem.


https://2.bp.blogspot.com/-zjUzNq6EruY/WzhzPthZ3YI/AAAAAAAAA7Q/b51AkrT7MgsPFp0WPr6lH9YizeLNr_7nwCLcBGAs/s1600/4.png

I already closed the shop and other ones are ok to get back to his inventory but only this painting is not available.
This is his painting. He painted this but how come he can't get this back? I can't drag it to his inventory.
Sorry I didn't see 'put it in inventory'
silly question..:(