I think i'd Photoshop that...... In fact I'm sure that image has been too, the light reflections on the bottle are identical (although slightly distorted/squashed), this wouldn't be possible when viewing a reflection through a reflection, you'd see a different effect.
It's a simple copy, flip, reduce height to 75%, reduce brightness, then transparent brush to regain the base of the glasses/bottle.
Working with black relective surfaces can be a nightmare. They say that black cars are the hardest to photograph......