Wikimedia Bugzilla is closed!

Flow's implementation of tooltips is not only different from desktop's watchlist notification but also broken on mobile (they cannot be read, being clipped off screen)

Mobile uses a toast module to deliver all notifications so this is a big inconsistency with the rest of the application.

Flow should be helping drive standardisation around this.
Take a look at 
mw.notify( 'foo' ) in desktop
and
mw.mobileFrontend.require( 'toast' ).show( 'foo' )
in mobile.