Resonance is not the same as "flipping".

Here's a metaphorical example that might help clear up this issue for those still struggling with it:

Suppose you, Leslie, are at a football game (or soccer, it's not crucial) and you have bet a large amount of money against your friend Alex concerning which team scores first. Your team is marching from right to left on the football field shown here.

(Original orientation of field)


Your team kicks a field goal (see above) and you claim your payment from Alex. Alex says "Wait a minute. That's exactly the same as rotating the field 180o as shown below and my team has scored, not yours. Pay me!"

(Rotated orientation of field)

Granted, the rotation looks the same as if the field goal were kicked on the other side, but that's irrelevant to the issue. Likewise, with resonance, we're talking about where the electrons are. If they can be on either end, for example, the fact that those two pictures look the same when you rotate the image is not the "point that's being made".