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

Calculating dependencies ... done!
Dependency resolution took 0.99 s (backtrack: 0/20).

[ebuild  N     ] app-arch/zopfli-1.0.3:0/1::gentoo  191 KiB
[ebuild  N     ] media-gfx/apngopt-1.4-r1::gentoo  565 KiB

Total: 2 packages (2 new), Size of downloads: 755 KiB