Pros
If you are on universal credit and haven't got much experience in the fashion industry, then this might be ideal for you temporarily as they offer a kickstart scheme. But don't expect to be doing creative tasks all the time - you might be counting wine stock, lifting heavy boxes up and down 2 sets of stairs or taking out the trash every now and then. You will be asked to work a trial week, so that's 5 full shifts, but you'll be paid your basic expenses. Company has a good history and will look good on your CV.
Cons
You are left in a very small and compact design room with one other person, who is the seamstress that works non stop all day. You'll be left alone to complete tasks with the sound of the sewing machine ringing in your ear, even when you get home. And it can be difficult to ask for help when english is not his first language and the employer is upstairs in her flat or in the other room busy with meetings. It doesn't seem like a sustainable place to work long term. The seamstress' work is not appreciated and is often talked down to. The employer will not recognise your efforts. Understand that being a studio assistant you'll be on the floor sweeping up threads and fabric scraps with a dustpan and brush as your not trusted on the machines. I wish I had known this before agreeing to trial. You are just there to make the company look good because whenever a client comes in as you are made to wear a calico coat with the logo.