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

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

[ebuild  N     ] media-libs/netpbm-11.16.1:0/advanced::gentoo  USE="X jpeg png tiff -postscript -rle -static-libs -test -xml" CPU_FLAGS_X86="sse2" 3753 KiB
[ebuild  N     ] dev-tex/tth-4.16::gentoo  330 KiB

Total: 2 packages (2 new), Size of downloads: 4083 KiB