The term "new faces" is one that is constantly popping up on modeling agency websites. While not all agency sites have them, a good majority do. As the name implies, new faces means male and female models who have just been discovered by that particular agency.
In general, a model listed under an agency's new faces division has little to no experience. In some instances it could include a model with prior experience but overall it is more closely associated with a newbie. Each agency deals with their new faces division in its own way so there are no hard and fast rules as to what I can tell you that will cover every modeling agency out there.
If you are a potential model who gains interest from an agency, they may start you off in their new faces division. At the office you'll have Polaroids taken of you, which the agency will post up on their website. Even though those photos are not professionally taken, they will be temporary until you have managed to get a test shoot done to begin your portfolio. Once you get that done, your agent will update your online profile with the latest pictures. Many times an agency will keep both the Polaroids and the professional images, since some clients want to see what a model looks like without all the hair, makeup and Photoshop. Sometimes a newly signed model will still be categorized under new faces even after he/she has done a portfolio shoot. This decision is entirely up to the agency.
Other modeling agencies won't put you right away onto their website if you are a new face and may do what is known as a "test" period, where they will submit your snapshots to current castings to see if any clients are interested in you. If a client wants to see you for a casting or go-see, the agency will send you to it and if you book that job, that is a huge plus and a great indicator that the agency should sign you. Agencies tend to do testing sessions for new models as a way for them to see how marketable they are before making a contractual commitment. It also allows the agency to gauge what their working relationship with the model will be. Needless to say, this arrangement--while up in the air and nerve wracking for some models--is an easy way for them to see if the model would work for the agency as an officially signed model. If they happen to have an issue or if the model shows signs that he/she is not a good fit or match, then the agency can simply let the model know they are no longer interested. Because the model was being "tested" the agency doesn't have to worry about terminating contracts or taking down photos from the website.
Becoming a part of the new faces division doesn't always mean you are a signed model and may not come with a contract. Think of it as a probation period: this is a period of time where you have no official ties with the agency so you are not yet a represented model. This isn't a bad thing--to even be considered a new face is a huge step over the competition. The decision as to whether an agency will stop testing you and offer you a contract will vary on a number of factors including, but not limited to: how well your snapshots are, if potential clients like your look and express an interest in hiring you or inviting you to a casting and how well you get along with the agency. You may be asked to submit more photos over time, which the agency will collect and use to shop your look around to clients.
If you are chosen to be a part of an agency's new faces division, that's great but you are also free to continue searching for another modeling agency. While going through the test/new faces period may be exciting and a step in the right direction, if you get an actual offer with a modeling contract from another agency, that is a better opportunity--especially if the agency offering to sign you is reputable and eager to start submitting you for work. If you find yourself in this situation, notify the agency you are testing with as soon as possible. Be professional and keep your conversation to the point. Simply tell them that you have found representation with another agency (no need to say what agency) and cannot continue with their testing/new faces process. It is a common part of the business so don't worry about hurting anyone's feelings. Agencies prefer if you let them know ahead of time so do it as a courtesy.
The situations and arrangements I've described in this post are not absolute. I wanted to cover some of the most basic new faces topics so I'm well aware that there may be some information I've either forgotten or aren't aware of. This is just general knowledge I felt would be useful to those aspiring models out there that are into their agency search and may find themselves in this situation. Ultimately, any and all questions or concerns should be directed to the modeling agency in particualr that you are dealing with. They'll be more than happy to answer your questions, especially if they have already expressed an interest in working with you.