would, up

Hi, is there anybody who can help me to explain the following sentences to me?

“Get a carton of eggs, would you.” What does the author want to say using “would you” Does it mean “Would you get a carton of eggs” ?

“Catching all the shoplifters who walk off with CDs up their jumpers” Does “up their jumpers” mean underneath?

Thank you. Gabriela

The placing of ‘would you’ in the first sentence seems to me to be more colloquial. My very correct, English lady mother-in-law would certainly use the second version.
‘Up their jumpers’ certainly means hidden underneath.