This shelf to hold your drink is in the restroom of a newly remodeled Starbucks in California I went to recently. It recognizes that you are likely to have a drink in your hand when you enter the restroom. It helps you out and makes Starbucks look smart.
This is a nice example of the Core Idea of proximity thinking, as well as a few ProxPatterns.
The Core Idea states that: In a situation, change elements, relationships and the proximity to better relate to each other. Starbucks added the element of the shelf to the proximity of the restroom. This helps other elements in the proximity, such as people and coffee cups, better relate to the restroom. It helps people better relate to elements like the toilet, sink and hand dryer. It keeps the coffee cup safer, cleaner, and easily reachable. Coat hooks perform a similar improvement for restrooms. Both get unneeded things out of the way temporarily.
You also might come to an idea like the restroom coffee shelf via ProxPatterns. You might, with ProxAwareness, notice there is no good place to put your coffee when you enter the restroom after you yourself get a cup. You might think, I wonder if something could be done about this (Value of Some). There might be other things people want to put down temporarily (Relate a Variety), so the shelf should be wider than just a cup. You might also use the transition smoothly ProxPattern, by placing the shelf next to the side of the door which opens, so people will see it right away.