Question

What does the fact that private companies own most media in the U.S. indicate to you?

Answer 1

That the private companies control the information and knowledge that is given to the population and therefore can control society into doing what they want them to do via ads, "news", entertainment (i.e. your favorite celeb does this so you want to do that), etc.

Answer 2

It can indicate many things! One of the main thing that it indicates is that most media won't be persuaded by government authorities, which means that the government has absolutely no forced say over what is on their media pages. If a source of media is owned by the U.S. you can know that it will likely contain bias!
If you have any more questions, please let me know and I will try to help you! I hope this was useful!