EDIT (Sept. 10, 2012): I was told that the gas company supplies them. I wonder how much variation exists across particular brands. BP seems to be very consistent and usually provides the smoothest interaction. END EDIT
The "Regular | Special | Super +" sign at the bottom does little aside from telling people what you can get out of this pump. Where do you think you push to actually select your grade of fuel? No, it's not the yellow sticker that says "PUSH TO START". It's the much less prominent colored areas above. It looks like any of these areas are programmable, but someone made the decision to only allow interaction with one of the potential choices (and they chose the less obvious one).
The screen the walks you through each step is divorced from the keyboard necessary for user input, so much so that a sign is needed to tell users about it.
There are three separate signs regarding payment, in three separate corners, in three very different styles, two of which are potentially confusing. Confusing sign #1: "BANK DEBIT CARDS NOT ACCEPTED". Since most (I'm guessing all, but I should confirm) debit cards can be run as credit, this is not quite correct from their customer's perspective. Confusing sign #2: "PRE-PAY ONLY...". This one can only be appreciated by viewing the image. The overwhelming message is that this pump is pre-pay only. However, after more investigation... cart was placed before the horse.
Where are these flexibility constraints coming from that put the interaction design onus on the convenience store owners? I've rarely, if ever, seen a place that offers more or less than 3 grades of gasoline. There seems to be no explanation for the variation across pumps.