It’s something that you see wine drinkers do - swirl their wine glass and then look at the ‘legs’ that run down the inside of the glass. And, often they’ll equate the quality of the wine with the legs by saying things like “Oh!…this wine has really great legs.”
It’s a real phenomenon, that involves some chemistry and physics, but I won’t bore you with the details.
The simple explanation of the ‘legs’ in a wine glass is that it’s all about the alcohol.
The droplets that form and move down the sides of the glass after the wine is swirled are a product of the fact that alcohol (ethanol) in wine, evaporates more quickly than water. The alcohol crawls up the glass as it evaporates, but since there is a film of water on top, it is pushed up in an arch. Eventually gravity causes the water's surface tension to be broken, allowing the water to run down, in ‘tears’ that form ‘legs.’
If you really want the technical details on this effect, look up the Marangoni effect.
So, yes, a great wine can exhibit great legs inside a wine glass. But the truth is that any wine can do that. Cheers!