This is a great observation! The blinking-indicates-editable-via-buttons-mode is a mental model you either have or you do not. It is certainly not axiomatic and

This is a great observation! The blinking-indicates-editable-via-buttons-mode is a mental model you either have or you do not. It is certainly not axiomatic and needs some experimentation to learn. Digital writwatches with those standard three buttons also relied on this mental model.