Please give some advice what to change in WP Gallery plugin that got hard reject

Hi, this is the second plugin that I have tried to publish.
Both got hard reject because of quality standards.

Second one is beautiful Gallery plugin with lots of options and easy to use interface.

Could you guys be so kind to review and write your opinion what could be the reason of rejecting.
Here is the link to download the plugin: https://www.dropbox.com/s/o9inoth3zuvqnox/photo-gallery.zip?dl=0
Link to demos: http://demo.grandwp.com/wordpress-photo-gallery-justified/

Thank you very much !