I'm upload the same aab package on Test Internal Track and on Internal App Sharing. And the result is soo strange: from the test internal app the download size is 44mb from the internal app sharing the download size is 75mb
I would has expected the same download size. Why are there this size difference ?
The difference comes from the compression of the APK.
When serving an APK from a testing track or the production track, Play compresses the APK on the wire. When possible, it also instead serves a patch with the difference from the previous version. This considerably reduces the size of what users have to download.
When serving an APK from internal app sharing, Play does not go through the trouble of compressing or generating patches since it's only for development / early testing purposes.
The files in the APKs should be the same whether the bundle is uploaded to internal app sharing or to a testing/production track.
The AAB contains the resources of your app in different languages, screen resolutions, ecc...
When you download an app from the Play Store, it will actually download only a part of the AAB, the part that actually is needed on your specific device (based on language, screen resolution, ecc...)
I think that this concept works on Test Internal Track, but not on the Internal App Sharing, because the Internal App Sharing is a lot more "debug oriented", (for example you can upload a debug build, you don't have to sing the bundle with your production key...) and so I think that with the Internal App Sharing you are actually downloading the entire bundle, not optimized for your specific device.
This can be the reason for the different download sizes, but this is just my opinion though :)
