Like a watermark on the left or right corner? 

no like if i share a link from a video page on a oxwall site to facebook i want facebook to see the video thumbnail and add that to their open graph so when it is shared on facebook users will see a link to your video page and a image for it also. 

This works with wordpress because wp downloads the image to the server and makes a og tag for it in the post. im sure this could be done in oxwall. 

its not just videos its just about everything does not have the og tags 

some plugins dont even have meta tags

everything is such a mess 

oxwall needs to make guidelines like

plugins must have a, b and c by  this date 
plugins must have d, e and ff by this date
plugins must be mobile site ready by this date 

plugins must have integration portal by this date
ie   rss plugin has a integration portal so plugin dev of say confessions can easy hook there plugins to the rss plugin

that would be awesome 

oxwall has so much potential 
have guidelines like that with a set date that plugins must comply by will weed out the crap plugins and open oxwalls potential

and make oxwall the best ever script 

and keep ppl using oxwall
95% now after vash there heads against the wall on battle just about everthing give up and leave oxwall

yesterday i went through mt mail messages from every one thats asked me for help there oxwall site and most have ditched oxwall for wordpress

i think oxwall should have some video tutorials out for the developers and sample code to show how to implement stuff like open graph, cloud storage systems, ( i noticed a lot of plugins on the market do not support amazon s3 cloud or other cloud storage's) and of coarse the most important is Seo.

JoshWho, Facebook parses different resources differently. As we don't have our own video uploader but only the embed video functionality, we able to share just existing image, description and title for links posted on Facebook. So presently there is no functionality to grab video thumbnails for Facebook by inserting the oxwall video link. This is considered as a custom code modification. To display the video  thumbnail on Facebook, you will need to have an existing video thumbnail for example near or up the main video window.

If you are not familiar with the code modification or plugin development, it would be better for you to find a developer who can help you. You can do it here: http://www.oxwall.org/market/specialists

i take it this will never be a future plan. its a real simple task. just grab youtube image like newsfeed grabs images and then embed the image link to a og tag.

Its ok im sure a 3rd party dev will make this happen one day.

JoshWho, we are thinking about improving our software constantly within the small team. Unfortunately, I can't affect our developer and product designer teams about implementation of new functionality, because I'm just a supporter.
For this goals we use our suggest board to show our product designers what features are the most essential.  It would be better if you make a suggestion on uservoice: http://oxwall.uservoice.com/forums/13756-ideas-for-oxwall .

i dont use the embed video plugin but it does grab the image in puts it on main videos page
newsfeeds etc 
so it should not be to hard for make it grab in and make it the og image on video view page 

uservoice has proved its just useless and a complete waste of time 
look at video uploader it had almost 1000 votes heaps more then anything else there 
only to be taken down with theres already one in the store
but they fail to see the one in the store has been and will always be useless