Maybe this is sort of an obvious answer and I am just overlooking a setting within the plugin. In the live demo (http://paratheme.com/demo/post-grid/?demo=ajax-load-more) I see that there are videos and Picture Sliders as thumbnails.
Where can I find the setting in which the post grid allows having a video or a slider as a thumbnail?
These are post formats features, if you have post format gallery and contain a gallery on post content then this gallery will display on thumbnail area, same a for video.
this feature must have on your themes currently activate, please see the screenshot what i mean
Please let me know for more help.
Awesome, that worked. Thank you very much for your help!