The right glas helps enjoying brandy even more.
Typically a snifter/cognac balloon is used. Brandy when becoming hand warm release more pleasant notes in the nose. So those glasses contribute to this by holding them in your palm and keeping the brandy warm.
I personally still find the drink rather aggressive in the nose when drinking from a snifter so I prefer a Grappa or even better a Nosing glass mostly known from Whisky. The later two unfortunately are not as elegant though but still do the trick with the warm palm (when held accordingly) and certainly help the nose to enjoy the spirit in all its dimension as well.
BTW – I have been to restaurants where snifter had been washed out with boiling water. Very interesting behaviour but not my cup of tea. 🙂