The Internal Sonic Progression in Bebe Rexha's "I'm a Mess"

The sonic development on a section-to-section level (e.g., prechorus-chorus) is usually straightforward to the listener. Most will also notice that on a large scale songs tend to get bigger and more climactic as they progress. But under the hood there are also more subtle internal sonic progressions that likely go unnoticed but contribute a lot to the effectiveness of the overall sonic arc. Here's a great example of such an internal progression that happens in the prechorus of Bebe Rexha's "I'm a Mess" (2018).