Getting new photos in a models' book is one of the most important things to the career and evolution of the fashion model. The book is like a CV, showing all the work experience and "level" of the model. Clients looking at the model's book can understand if this model is a working model, if she/he has enough experience to handle the job, and of course, what they look like on camera.
Many times models travel to a country and stay for 3 months, and then return to their hometown or move on to another market, leaving their past agents to collect any photos/tearsheets that they maybe have done, but had not published during their time in that country. This can often be a nightmare as agents have a new batch of girls coming into the country and have already forgotten about the last model. As their business is on turnover, they are not concerned with "the last batch", unlike in markets such as Europe, where the models may return periodically, Asian markets often have the models leaving and not returning again. So the question is, how does the model manage to collect their tearsheets?
First, as a model, try to get as much information about the client, the name of the client, or photostudio as possible. We all know it's not professional to take the contact information of the client, photographer, etc and may make your agent mad if you do so--they may think that you will work with them directly. However, in markets such as Asia, I would recommend most definitly to get the telephone number/email of the assistant, photographer, or the photostudio, and then if your agent doesn't follow up, I most certainly contact them. For example, I have been chasing these photos here for 6 months because I knew the shooting was so successful and great photos. Asking my agent repeatedly, he got no results for whatever reason. I finally asked him to give me the contact of the client so that I could try. The client finally gave me 3 photos from the shooting for my book.
Persistance. The only way is to keep asking your agent. Keep it in their mind--they have so many girls to take care of you will need to send them a reminder. If this is not successful, then go for the client and write them a sweet note thanking them for the job and asking if you could receive any beautiful photos from the shooting. If they were to ever ask you to work with them directly, you can simply refer them back to your agent for any job booking. This way you avoid any conflicts and return the client to your agent for work matters and you still get the photos for your book.