What is the difference between this bank and other banks like HSBC and BEA in Hong Kong?

It is not a bank, but a financial institution licensed by Statrys to operate as a money service provider in Hong Kong and as a small payment institution in the UK, regulated by the Customs and Excise Department and the Financial Conduct Authority in the UK. Client funds are held with a partner bank (DBS Bank), which is one of the largest banks in Southeast Asia with a banking license.