https://screenshot.googleplex.com/F5Ggo1ymDvf

The top two entries here are "device affinity broken, affecting N tests". This is a good way to summarize a huge set of purple steps that are all due to the same root cause.

However, all the lower entries are actually the same thing. The Android Nexus5, Nexus6, and Nexus9 Perf bots all have broken device affinities, and those are causing test steps to be purple, but for an unknown reason they're not getting grouped into the rows at the top.