As you probably know, LinkedIn and the sending softwares you use do not contain HTML or 'Code View'. Therefore you cannot use the normal snippet.
But that does not mean that Vinna does not work with LinkedIn. Simply use the link to the video and it will show the animated GIF just like it does on email.
Here is a quick tutorial:
Head over to Campaigns and find the Video Project you want to use.
When inside the video project, right click one of the Preview videos:
Head over to your sending software or LinkedIn.
Go to the sequence you want to send it on, or to the person you want to send it to.
Paste the link in there:
Change the email in there to either:
The email from the lead you are sending the video to.
The email variable from the sending software you are using.
Remove the "Preview" from the link:
Done.
If the video project is generated correctly and you have set it up correctly, it will display the GIF as usual and when clicking they land on the landing page you created.