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

Calculating dependencies ... done!
Dependency resolution took 1.09 s (backtrack: 0/20).

[ebuild  N     ] media-libs/giflib-6.1.3:0/7::gentoo  USE="-doc -static-libs" 460 KiB
[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     ] x11-libs/libXScrnSaver-1.2.5::gentoo  USE="-doc" 266 KiB
[ebuild  N     ] x11-misc/xplanet-1.3.1-r4::gentoo  USE="X gif jpeg png tiff truetype" 1208 KiB

Total: 4 packages (4 new), Size of downloads: 5685 KiB