The map uses the H3 tiling system, and the cells displayed are resolution 4. Sometimes for specific cases I look at higher resolutions. For example, I believe this map I did during the still-unexplained Dallas-Fort Worth major interference event of 2022 uses resolution 6: https://twitter.com/lemonodor/status/1582403839004508160

The caveats of that tweet still apply to higher resolutions: Specifically that you start to see the effects of individual aircraft, which can be harder to interpret.