The artwork for the first DVD volume has been added to the official site.
The limited edition cover by character designer Megumi Kadonosono:
And the regular/rental edition cover by mangaka Yukari Higa:
To re-post something I added as a comment previously, I recenty obtained a CD-R of colour settei sheets for the series, and it includes names for some of the background characters. I've made my best guess at translations for them since the romaji on the sheets looked dodgy, and they got Éclair and Lumière's names wrong.
The receptionist with brown twintails is Lala (ラーラ Raara)
The receptionist with straight black hair is Matsurika (マツリカ)
The waitress with short blond hair is Felicie (フェリシー Ferishii)
The waitress with short brown hair is Mia (ミア)
The waitress with the black side-pony is Jin-hwa (ジンファ Jinfa)
In the same shipment of auctions stuff I also received a promotional postcard, a wallscroll and a promotional desk calendar for the Ignition movie: