/usr/lib/python2.7/dist-packages/IPython/frontend/html/notebook/static/jquery/css/themes/rocket/images/ui-icons_eaffb9_256x240.png is in ipython-notebook 0.12.1+dfsg-0ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/python2.7/dist-packages/IPython/frontend/html/notebook/static/jquery/css/themes/rocket/images/../../../../../../../../../../../../../share/pyshared/IPython/frontend/html/notebook/static/jquery/css/themes/rocket/images/ui-icons_eaffb9_256x240.png