I think there's maybe a difference between the witness situation on hive and wax. I'm not very familiar with Wax.

As far as I know voting for witnesses on Hive has nothing to do with earning passive income. The witnesses move up the table of earnings depending upon how many votes they get but voters don't get any rewards.

The proxy simply means that you will vote for the same witnesses as your proxy. So, in your case, by choosing @theycallmedan you will be voting for the same witnesses he does.

Hopefully someone will jump in and correct me if I'm wrong.