What caused the breif period of contentment for Liesel and Papa Hubermann during the the summer of 1942?

I think this is when Hans gets a little work painting people's window blinds black.

Liesel goes with him on the jobs. She watches him mix paint. For a little while reletively pleasant.One day, when they are painting at a wealthy home, Hans and Liesel are invited to the kitchen and Liesel has her first taste of champagne.