It's tough to tell in the pics if the white streaks are from excess wax or too little (dryness). Scrub at it with Scotchbrite. If the white streaks go away, you just had excess wax and buffed them out. If the streaks remain, then you stripped the wax when you used the brass brush and need to rewax. That brush should only be used to help strip away old wax, before you wax. It's purpose is to pull old wax and dirt out, so you don't lock the dirt in with new wax.
Waxing really is simple. Strip the old with a brush, wax on, scrape off, and buff.