40inch Panasonic tv

[userl82ULy85QN]

I have finally figured out how to mirror my Samsung tablet to my TV but the picture is tiny. My TV is only set for streaming with a roku stick

[nullandvoid]

When you cast your phone screen to your TV you cannot change the aspect ratio.  You will get an image of your screen in the scaled dimensions of your device. It does not expand to fill your TV screen. 

[meself]

Not sure you can expect the phone to match the tv screen