Like the TV Day of the Triffids from the same year, the style reflects its times as much as its source material written in a different (postwar) era. But I wish I could have found some stills or clips of the genre-breaking and apparently even more criticised aspect from the original book -- the breakdown of reality leading to an escape into another world.
"'D' is a chronicler of a society in chaos, who looks down on the marauding gangs, and rubbish-strewn streets from the fortress prison of her flat. Buffeted by inner dreams and longings, D finds an alternative world by stepping through the wall of her flat, like Alice through the Looking Glass. Here it is Victorian England, the bosom of an unsettled family, harbingers, perhaps, of the decay to come. She flits between the two sides of her double life, always observing, never participating, and watches as her protégé, Emily, becomes involved with vagrants' leader Gerald and their efforts to control the violent scavengers fail." IMDB.