I have a cat and I noticed that the communication is mostly cat -> me. Not really the other way round. She is very capable to express what she wants, but my at

I have a cat and I noticed that the communication is mostly cat -> me. Not really the other way round. She is very capable to express what she wants, but my attemps not so much. Except when I make certain weird noises (a specific set). She will wave her tail a bit every time, whether she is sleeping, or staying at something invisible, or looking at the roomba. I always wondered what this tell wave mean (it is just the sun's, they're is no followup afterward)