The onion shape was popular in the period and this larger style of the bottle features the extended neck. This particular style is perfect for a dinner table setting. Green glass bottles and onion bottles specifically were the preferred method for shipping varieties of wines through trade routes. The green color in the glass reportedly keeps the alcohol from light damage.
I like the color and shape of the bottle, and although it appeared rather small I was surprised at how much it holds. I was a bit disappointed to see a made in China sticker on the bottom, but overall I am pretty please with this bottle.