I'm a relatively new user to sailfish and am very impressed. As a linux user i appreciate having live multitasking - especially the ability to view the multitasking screen via the covers.
my main issue with the cover screen is identifying which app is which. some,such as the galley app are very clearly defined by thumbnails of photos. Others,especially if they contain text are hard to instantly identity. The issue grows as you use more and more apps.
Could i suggest that the live cover tile inherits its launch icon from the app grid. The icon does not need to be fully sized, but should be in full colour (as in the app grid). This way a consistent identification of app from icon to minimised version can be maintained.
Given that it is important not to obscure the live cover, perhaps the app icon could be slightly offset from the left, just slightly overlapping the left edge of the cover. (I think there is enough padding between covers to allow this). OR the icon could be overlaid on the top edge. This would leave the bottom of the cover free for cover actions.
I have shown a couple of examples below. Obviously the cover content will need padded to avoid it being clipped by the cover icon but it seems like it might work well with text-only covers. It would mean that people can follow a consistent visual message from app-dock to cover while still maintaining cover actions AND content previews. These are a major strength of sailfish I believe!