U.K.'s Johnson Says Shops Will Be Able to Re-Open From June 15

The transcript discusses the reopening of nonessential retail, including department stores and small independent shops. This reopening is contingent upon meeting specific conditions, such as progress against five tests and ensuring that retail premises are COVID secure.

How does the reopening of shops relate to the progress against the five tests?

What does it mean for a retail premise to be 'COVID secure'?