Cards move while thumbnails for videos are generated

This issue happened on the BQ, with the image: stable/aquaris.en and after installing the new thumbnailer from silo 10.

To install the new thumbnailer from silo 10:
$ sudo apt-get install upgrade && sudo apt-get install thumbnailer-service.

I've created 2000 hard links to an existing video found in the Videos folder.

Right after installing the new thumbnailer and rebooting, open the gallery-app.

Cards start moving while thumbnails are generated.

You can see a video of the issue here: https://www.dropbox.com/s/ufem6a13uhmazg2/20150626_122831.mp4?dl=0

Between tests you can clear the thumbnailer cache with:
$ thumbnailer-admin clear
in order to force the thumbnails generation.