Code review comment for lp:~mzanetti/unity8/fix-lockscreen-wallpaper

- I might like a comment above the 0.4 alpha rectangle in Lockscreen to the effect of "This is only here to match the alpha of the main wallpaper for the greeter" -- makes a person wonder why its there otherwise

- We don't want to drop support for gsettings. That fallback is used so that image customizers can set a different default wallpaper. (They can easily change gsettings defaults, but not AS ones)

- I don't see design sign-off for this. I asked Olga about this in person in London and she preferred them to be separate backgrounds.