Samsung S8 supports HDMI function and can output pictures to TV for display.HDMI cable and HDMI adapter need to be purchased separately.
Samsung S8 display method:
Connect the HDMI adapter to the phone.
Connect the HDMI cable to the HDMI adapter (type C USB to HDMI), and then connect to the HDMI port of the TV or monitor.
You can also open the ”Samsung connect” that comes with your mobile phone, search for devices under the same wireless, and select TV to connect.
Audio, video and pictures can be displayed directly.
Another way to display a mobile screen onto a smart TV:
The condition of use is that you need a miracast smart TV as the miracast receiver to receive signals from the galaxy S8 mobile phone.
When your TV and mobile phone are connected to the same local WiFi network, draw down the “shortcut menu” from the top of the screen and click “smart view”.
Click “smart view” on the galaxy S8 phone to find the available miracast receiving device – Smart TV.
In the same network, “smart view” function will find the surrounding available miracast receiving devices, such as your smart TV.

The screen image can be achieved by simply selecting the TV name. But the downside is that you have to buy a brand new Samsung smart TV and set it up to work.