I was approached the same way by Talent100 and went through the whole process as I figured that it would be good to provide the details so that others won't get scammed. When you go into casting, you will bring photos of yourself, you will fill out a form, see the talent director, afterwards you will go into a room where they will film your "audition" which consists of an introduction of yourself and a skit where you pretend the camera is your friend.
When you're done they'll tell you they'll phone you when a job comes up. They'll phone you three times, this varies, see other forums, on three separate nights saying they have sent your photos for jobs. They will then make one last phone call saying they have received good feedback or that they have a job for you, this varies, see other forums, and as a result, they would like you to come back to see the talent director.
Once in the director's office she'll say how great you are, how much work you'll get, etc., this varies, but basically it's all flattery. After about a half hour of this flattery she'll state that you'll need to pay for a portfolio, about $4000 or so, and that the photographer is not affiliated with the company so whatever you pay will not go to the company.
The thing is the photographer will use the agency's office for the photoshoot. Then she'll say that you'll need to pay to have yourself posted on their website which is about $8000, which is how companies find you and how you can apply for jobs. Then she'll say they have a job that is waiting for you.
Once you start questioning the fees she'll say this is the way it is in Hong Kong. Once you she sees signs that you aren't going to pay she'll then ask you to leave. Of course, if you don't show that you can't be taken for a ride then she'll continue her pitch until you pay. Of course there will be some variations, for example, if you already have a portfolio then they'll try to get you on the acting course, etc. If this "agency" does try to scam you it's actually pretty easy for you to see it's a scam.
During the phone calls and the sales pitch by the director it seems like they are reading a script, there is really no sincerity in their voices which is funny since it's supposed to be a talent agency you'd figure their acting would be better than that.
Please remember if you would truly like to enter the entertainment industry in Hong Kong you will either need to know someone who is in the industry already, sign up with a reputable agency like JamCast, or enter the Mr Hong Kong or Miss Hong Kong Contests, which even these days requires that you know someone at TVB. In addition, whenever an agency says you'd make a great model, actor, etc., then why would you have to pay them?
If they really do believe in you then they should be investing money in you not the other way around. If some of you out there have been scammed please don't feel down as they will try to scam everyone even those who have talent and who are of model quality, like the member's wife who is an ex-model. Hope this helps to warn others out there.