my guess is a
hd link box or box like it that sits in between the mylink base unit and the screen which gives you a hdmi 2 gvif port which allows you to use the mylink screen as a display and plugin android boxes etc.
in one video he is using smart view(screen share) from the phone to a reciever box which would probably be android powered.
in the other video it looks like he is just using a android box with android tv installed on it which is probably the same box used to screen share from the phone.
typically you need to use the mylinks "bluetooth audio" or the "aux audio" input for the audio from these boxes and some will not have touch functionality from the mylink screen to the android box and they will use a external remote.
there have been a few iterations of this style of setup with the very early ones being crappy because of the cheap android box used.
envyous customs does one that is similar.