These are the packages that would be merged, in order:

Calculating dependencies ... done!
Dependency resolution took 1.02 s (backtrack: 0/20).

[ebuild  N     ] mate-base/mate-common-1.28.0::gentoo  69 KiB
[ebuild  N     ] x11-themes/mate-backgrounds-1.28.0::gentoo  45708 KiB

Total: 2 packages (2 new), Size of downloads: 45777 KiB