media-libs/jpeg-mmx-1.1.2 does not exist anymore (it was a typo), and now, latest version available is media-libs/jpeg-mmx-0.1.6. So now, media-gfx/showimg should depend on >=media-libs/jpeg-mmx-0.1.6. Bug #100565 shows the same issue for media-video/mjpegtools.
Actually, the resequencing of the version numbers for jpeg-mmx breaks the ebuilds for mjpegtools and libmovtar. In each case, modify the respective ebuilds to depend on >=media-libs/jpeg-mmx-0.1.6 i.e. assuming "x86 ~x86" then modify: /usr/portage/media-video/mjpegtools/mjpegtools-1.6.2-r4 /usr/portage/media-libs/libmovtar/libmovtar-0.1.3-r1 I wouldn't know about other architectures.
Note that this is _different_ from bug # 100555
media-gfx/showimg depends on media-plugins/kipi-plugins depends on media-video/mjpegtools => fixed in Bug 100554 *** This bug has been marked as a duplicate of 100554 ***
*** Bug 100575 has been marked as a duplicate of this bug. ***