Some sites are somehow displaying video preview thumbnails for pages that contain flash games in google search results. For example search for:
I see this only on small sites which makes me believe google is not very happy about it.
How do they do it and is it ok with google?
I assume they are submitting thumbnails through video sitemaps, but I can't find any information about using them with flash games. I also run a few such sites through rich snipped testing tool and it didn't detect any microdata tags on a page.