Perhaps not the best example for how abstract something is. The 18650 battery cells that most electric vehicles use looks very similar to an AA battery. You certainly couldn’t tell them apart from an icon.
Apologies for the late reply, only just saw your question. In case you haven’t answered it yourself: Some appear to have the “button top” that you know from AA’s but most appear to omit those. But even those without the button top have a smaller contact on the positive side similar to the button top.