App Download Size Nag Email - "Universal" device type

Whenever we submit a new release to the App Store we get a nag email from Apple that states, "The app binary listed below was 199.2 MB when you submitted it, but will be 223.9 MB once processed for the App Store. This exceeds the cellular network download size limit and may require your app to be downloaded over Wi-Fi."

However, when I download the app from the App Store and have the Settings set to "Alway Ask" on my phone the alert shows 129 MB, which is matches up closely with what we see in the TestFlight metadata for all device types except "Universal".

What is "Universal" device type in these days of thinning? And why is Apple apparently using that number to generate the nag email?