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

Calculating dependencies ... done!
Dependency resolution took 1.66 s (backtrack: 0/20).

[ebuild  N     ] media-libs/giflib-6.1.3:0/7::gentoo  USE="-doc -static-libs" 460 KiB
[ebuild  N     ] acct-group/epmd-0-r3::gentoo  0 KiB
[ebuild  N     ] acct-user/epmd-0-r3::gentoo  0 KiB
[ebuild  N     ] dev-lang/erlang-29.0:0/29.0::gentoo  USE="kpoll ssl -doc -java -odbc -sctp (-systemd) -tk -wxwidgets" 65437 KiB
[ebuild  N     ] media-libs/libwebp-1.6.0:0/7::gentoo  USE="gif jpeg opengl png tiff -static-libs -swap-16bit-csp" CPU_FLAGS_X86="avx2 sse2 sse4_1" 4196 KiB
[ebuild  N     ] dev-util/rebar-2.6.4-r1::gentoo  209 KiB
[ebuild  N     ] dev-erlang/p1_utils-1.0.29::gentoo  48 KiB
[ebuild   R    ] media-libs/gd-2.3.3-r4:2/3::gentoo  USE="fontconfig jpeg png tiff truetype webp* zlib -avif -heif -static-libs -test -xpm" CPU_FLAGS_X86="sse" 2744 KiB
[ebuild  N     ] dev-erlang/eimp-1.0.23::gentoo  3398 KiB

Total: 9 packages (8 new, 1 reinstall), Size of downloads: 76488 KiB

The following USE changes are necessary to proceed:
 (see "package.use" in the portage(5) man page for more details)
# required by dev-erlang/eimp-1.0.23::gentoo
# required by =dev-erlang/eimp-1.0.23 (argument)
>=media-libs/gd-2.3.3-r4 webp