From a practical point of view this makes most sense. If something ‘within’ the bounds affords pressing, anything at all, then some part of the large bounded area would get pushed.

But, even then, the philosophical question remains, why even the large area? Why do the areas between these large ‘buttons’ not persuade us to click? … and why, whatever attracts, is this not under conscious and rational control? Why do I ‘forget’ what to press in this situation?

It affords pushing. It seems to be the logical thing to press.

Conversely the tea option is a very light and clean image, with the ‘free’ sticker (it looks like a sticker, rather than an integral part of the backlit graphic) plonked on at a bit of an angle. The fact that the text is a bit skewed may be a subconscious indicator that this is information and not calling you to press. The call to action here is clearly visible.

As for the whole thing being a button. I’d find that very unusual and uncomfortable. That would possibly require the use of more fingers, or even a palm press to activate the switch and get your dried leaves in boiling water. Apart from the mechanical aspects.

Perhaps it not so much a button problem as a sticker issue and the question should be why does the price sticker look like a button?

‘All my circuits are irrevocably occupied trying to work out why the earthman wants boiled leaves’