Since the idea of the Kendo UI Chat is to be framework agnostic, we only included the hero card out of the box, since other frameworks (like DialogFlow for example) use different format for their attachments. We left the definition of other attachment types to the developer by allowing for easy definition of templates in the bot.
Here's a small dojo which demonstrates how you can add a template for the video attachment type in the Kendo UI Chat:
If you change the directline key to the one you're using you will be able to see the new template when the video attachment is received. Please note that the provided template is a placeholder, and it's up to you to define the exact html, based on the response from the bot.