From the release notes:
“A whole new default icon theme has been created for 2.4. The
icons comply with the Tango style guidelines so GIMP doesn’t feel
out of place on any of the supported platforms. Regardless of
whether you run GIMP under Microsoft Windows, Mac OS X or Linux
(GNOME, KDE or Xfce), GIMP provides a polished, consistent look.
“Additionally the icons also have enhanced usability on dark
widget themes, which is a common setting among digital