fresh...

...and a 'first' to have a 'long black' served on a  little wooden paddle with a glass of spritzy mineral water.

A variety of reasons as to why but the owner of this cafe said it was served as a palate cleanser between sips and only with black coffees.
Others include:
'feels very European and sophisticated and is a most welcome trend'....yeah right
'sparkling water helps with the intensity of the hot, black drink and is used as a palate cleanser between sips'
"If you are tasting the coffee to appreciate different flavours – single origin, for example – it will help you to filter out some of the more intense flavours."  

http://www.goodfood.com.au

Also...and this is an interesting one... a sparkling long black:
'basically a frozen latte glass containing a ristretto topped up with iced mineral water. It’s a cooling summer coffee for those of us who aren’t so fussed on the creamy, milky or sweet iced coffees'  http://www.corridorkitchen.com