What's going on with Naomi Osaka At The Superbowl?

So I saw a thread pointing to this video where at the beginning we saw Naomi crying a bit:

https://www.youtube.com/watch?v=jCm3BemDlj8

Apparently there is some controversy that I didn't quite understand. Can someone please explain this one for me. I watched the superbowl but I came in late and I probably didn't pay attention to everything