Thank you for posing in the answers forum! That is a great question. It all depends on what type of phone you have. If you have an iPhone, you can get a cable that converts the charger plug for the iPhone into an HDMI cable and the HDMI end will plug in to your television. However, using a connected device, such as a Netgear Neo TV or Western Digital TV, is the supported way to connect to your Slingbox on your TV. I would recommend using this if you are looking for the best possible picture.
Hope this helps!
The Sling Moderation Team