This is the front section of Gringotts. Upon entering, a new guest must first follow one of the two spiral staircases to the second floor. This is the office of new accounts. Here, (in the middle of the 2nd floor), a goblin (actually a robotic figure remotely operated) signs up new accounts. The human operator keys the relevant information onto a computer and the goblin's hand grabs a piece of dusty old paper and proceeds to write out the contract in cursive script.
Customers are encouraged to dress up like characters from the movie. Unfortunately, not everyone looks exactly like a Harry Potter character, so quite a bit of variance is seen. For instance, this customer is attempting to play Hermione, but the customer has red hair that doesn't quite fit.
The rear of the main bank chamber houses several offices. On the right is the mortgage loan broker. Customers can apply for new home loans here. The goblin (again a robotic figure) looks into his crystal ball to discern the correct interest rate for the current conditions of the loan. Mortgage rates at Gringotts are typically a bit higher than average (and savings rates a bit lower) to pay for the cost of all the banking entertainment. BrickTopia citizens don't mind this though as they are generally quite wealthy.
On the far left is the vault master. This goblin arranges appointments with customers to ride into the vault. For customers lacking the time for the lengthy (but fun) cart ride into the vault, there is the ATTM.
The ATTM (Automatic Troll Transaction Machine) allows fast banking transactions for customers not having the time for a ride into the vault. Customers write down their secret code on a piece of paper, check off a box indicating the desired transaction type, and hand it to the troll (who is completely computerized and requires no human behind the scenes). The troll uses the latest ICR character recognition technologies to read the information and then perform the correct action.
Unfortunately, the Troll sometimes cannot read the information. Originally, the troll would say "would you please write that again," but customers got irritated. Instead, the "reject" behavior was changed to have the Troll menacingly wave his weapon and growl at the customer. A sign was tacked up showing the correct way to write all characters as well as the correct spacing. This sign includes the note: "WARNING: This troll is near-sited and may become dangerous if he cannot read your writing. For your safety, please make your letters and numbers as follows..."