Answer
Neither "left and right" nor "up and down" are inverted in the mirror; it is "front and back" that are inverted.
Work Step by Step
When you wave your right hand, the image of your waving hand is still on your right, directly in front of your hand.
Similarly, your head's image stays directly in front of your head, and your foot's image is still directly in front of your foot.
This is illustrated in Figure 28.8.