The British Heart Foundation's director of policy and communications, Betty McBride, said: "Tobacco advertising is rightly banned in the UK, yet current glitzy packaging clearly still advertises tobacco on the cigarette box.
"It's an absurd loophole the tobacco industry takes full advantage of to lure in new young smokers."
More top news
The memorial service will be attended by Prince Harry and Meghan Markle.
David Browning admits manslaughter by diminished responsibility but denies murder.
Four people have died and the suspect is still at large, police said.