Featured images

Hi,

My featured images darken when you hover and are clickable in a way I can’t really explain. I don’t know if this is a setting or a plugin, but I cannot find a way to change it. Does anyone know why it is doing this? I have tested in incognito and other browsers where I’m not logged in.

https://goo.gl/0jxFzG

http://www.shakeuplearning.com/blog/winter-magnetic-poetry-with-google-slides/