Are you talking about MOVIETUBE website or some metro app in windows 8.1?
And it kind of helps if you mention the Model number of your Smart TV and your computer. The hardware on your computer determines if you can send something to your TV and how you send it. The mention of DLNA above being enabled, well, anyone who knows
about Smart TVs, knows that answer and it is YES. In general, I know Smart TVs supports DLNA. But Smart TVs may support Widi also, pending on how new they are. And if you have INTEL Widi onboard your computer, and the Widi software, you can Mirror your laptop
to the Smart TV. Or you can buy a Widi device and put it on your computer. Actually, in order for anyone to answer your question, they need to know more about your computer, the OS, the Hardware, and your TVs system and Hardware it supports. That way you
can determine weather or not you need to purchase something to use your TV as a Wireless display. And using it as DLNA, you usually need the Video already on the HD to play. However, Chrome has a Plugin, that I found that will play Video from a website,
and I am not talking about ChromeCAST plugins, but a different one, but you need to install two extensions or apps to do this in chrome.