Same, but it still seems unintuitive and pointless. Why not just keep them going from left to right? I'm pretty sure the target audience for this only really cares about the content and anything else just gets in the way.
Personally I use it to map my presentation into chapters. It allows me to better know where I'm at while presenting, and allows people reading my slides to get an idea of how it's laid out inside my brain.
It was just used by a colleague to organise his slides into:
Topic
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Code example
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What that code renders into
The last slide was actually rendered live from the slide before it. Absolutely badass.
