As an ex-Android user and ex-QA guy for some of the Android software: by the "things work as they should (i.e. as you expect them to work), without lags or bugs that can drive you mad".
One of my ex-collegues is now working for one of the android-phone manufactures and by his words the whole process of creating the the new device is basically trying make shit work good enough to pass Google's tests (something is going wrong with hardware? fuck it, we'll fix it in software later), then releasing a bunch of patches, then new phone, because nobody will ever invest their time into makeing the currect device to work with new Google's test. It just won't.