Hey Johannes!
The example page uses pano2vr. There is a wordpress plugin for inserting pano2vr 360 panoramas: http://ggnome.com/doc/pano2vr/5/cms-wordpress/
But it works with a shortcode and for now lay theme doesn't support shortcodes.
But you can embed things using an iframe embed in the gridder with "+More"->"+HTML". Here is a tutorial about how to create a panorama view (google embeddable vr views) and embedding it using an iframe: https://www.sitepoint.com/embedding-virtual-reality-across-the-web-with-vr-views/
I don't know about making them play without fullscreen or something like that.
If you want I can send you a login to a layteme testaccount so you can try it out.