But . . . here are some cues to the outside world:
High Life is a pilsner beer brand of Millers, the American brewers. It is very fizzy – could that account for all those black ‘bubbles’-like strata of carbonated beer in a glass which form the background of the print?
‘High Life’ could also refer to ‘substances’ – it’s 1967 after all. Those fuzzy horizontal lines in the centre rectangle could suggest weed-affected vision. And, maybe, those sharp, brightly coloured diagonals are channelling us through those gates of perception apparently unlocked by Lysergic acid diethylamide.