You can cast your Moto G5 Plus phone’s screen using Chromecast, by doing this you could see the pics, videos and even when you play games can be displayed on the TV. But you should be having a Chromecast connected to your TV. Once you switch on your TV with Chromecast connected, turn on the WiFi on your phone and pull down the notification area where you can see the option Cast. If not click the edit button on the next screen, drag and drop the Cast icon.
Now click on Cast, it will connect the Chromecast on your TV. You can now see your phone is mirrored. Whatever you do on your phone can now be shown on your TV. Play videos, show pics, play games anything you do is shown on the TV. Tilt your phone while playing movies, so that you can see the full screen.
The beauty of this feature is during casting you can turn down the screen so that the movies are still playing on your TV, also you can switch on to other apps like whatsapp and start chatting.
The other way of casting is, open Youtube and play some clips. On the top of Youtube there is a cast option. Tap on that which will connect to the Chromecast and start playing the video on your TV. So using Chromecast you could cast the videos or even mirror your phone without any third party apps.