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

Calculating dependencies ... done!
Dependency resolution took 1.01 s (backtrack: 0/20).

[ebuild  N     ] virtual/jpeg-100-r1::gentoo  USE="-static-libs" 0 KiB
[ebuild  N     ] media-libs/libmng-2.0.3-r1:0/2::gentoo  USE="-lcms" 930 KiB

Total: 2 packages (2 new), Size of downloads: 930 KiB