Best case scenario: It's tragic that someone who has reached Drake's level of success finds any enjoyment from gambling on such a weird setup and it's clear by the tiny amount of views the stream had, not many followers are even interested in it either. Worst case scenario he is playing these games with the hopes of drawing his followers in and has a hidden agreement with Stake to advertise their site (beyond the official sponsorship he has picked up with them). It is very likely that none of his own money is at risk during this session, which is why he seems quite content and happy, because not only does he get paid to do this gambling, he is never losing anything like a regular player would.