InMail is a paid service that allows you to send private messages to people on LinkedIn who are not direct connections.
To share videos through InMail, simply copy and paste the link to your video in the message.
When sending a message to one of your direct connections, LinkedIn will "unfurl" the link to display a message that includes the title of your video, an image of the video thumbnail with a play button, and a plain text link to the sharing page. When the recipient clicks on the image, the video will open in a separate browser tab.
When sending a message to someone who is not one of your direct connections, the thumbnail of the video will not be displayed, but the recipient will still be able to click on a link that will open up the video in a separate browser tab.
If the recipient has responded to one of your messages already, you may notice that the thumbnail will populate for the next video you share with them.
The Share to LinkedIn option that you can use in Vidyard is a standard LinkedIn sharing option. This does not have the compatibility with InMail to show contacts that are not already in your network.