Currently the homepage slideshow is not working properly. Due to a packaging or build issue.
This looks like a packaging issue with the nivo-slider library the zip contains the following directory structure.
The drupal.org install profile packaging script extracts this (correctly) as follows;
The 2.6 version of nivo-slider was not packaged this way. However, the 2.6 version of nivo-slider is not available through the whitelisted github urls. Unfortunately the problem persists in the 2.7.1 version.
A workaround is to manually fix the library structure with some commands similar to the following;
mv ./nivo-slider/* .
rm -rf ./__MACOSX/
drush cc all