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

Calculating dependencies ... done!
Dependency resolution took 1.00 s (backtrack: 0/20).

[ebuild  N     ] x11-libs/libXv-1.0.13::gentoo  USE="-doc" 275 KiB
[ebuild  N     ] x11-libs/libXvMC-1.0.15::gentoo  278 KiB

Total: 2 packages (2 new), Size of downloads: 553 KiB