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

Calculating dependencies ... done!
Dependency resolution took 1.59 s (backtrack: 0/20).

[ebuild  NS    ] app-text/docbook-xml-dtd-4.3-r2:4.3::gentoo [4.1.2-r7:4.1.2::gentoo, 4.2-r3:4.2::gentoo, 4.4-r3:4.4::gentoo, 4.5-r2:4.5::gentoo] 82 KiB
[ebuild  N     ] xfce-base/libxfce4util-4.21.0:0/7::gentoo  USE="-introspection -vala" 113 KiB
[ebuild  N     ] x11-libs/gdk-pixbuf-2.44.8:2::gentoo  USE="gif jpeg tiff -gtk-doc -introspection -test" 5897 KiB
[ebuild  N     ] xfce-base/tumbler-4.20.2::gentoo  USE="jpeg -curl -epub -ffmpeg -gstreamer -odf -pdf -raw" 695 KiB

Total: 4 packages (3 new, 1 in new slot), Size of downloads: 6786 KiB