Hi eagtperez,
Thanks for posting here in the Google Nest Community. I’m assuming that you’re casting either a screen from your smartphone or a computer. Usually, when casting a cast-enabled app from a smartphone or a Chrome browser tab from a computer, it occupies the TV’s entire screen. But when you cast a screen (mirroring), the TV renders depending on the resolution or screen size of the casting source. Some of these can be adjusted, but it depends now on the casting source (smartphone, tablet, computer, etc.).
I hope this answers your question. Let us know if you still have other concerns.
Thanks,
Kimy
