Man, the U.K.'s degeneracy has layers.
First, it's even legal for a store to require a certain age to buy something that doesn't legally.
Second, a store requires a legal age for energy drinks of all things - not gonna say it's healthy, it's definitely not, but it's unhealthy in ways we are absolutely surrounded by these days.
Third, to comply with that policy that barely makes sense in the first place, the employee (no doubt because it's another dumb policy, not blaming some store clerk for just going with the flow) asks for the I.D. of someone who supposedly looks 25.