[ Spoiler ] Qualification Lap Question

I was just wondering if anyone knew what exactly Hamilton is doing with his left hand at 0:46 & 1:45 in this video?

http://www.bbc.co.uk/sport/0/formula1/17498497 (BBC, so UK only unfortunately)

I have to say superb lap by him, and he could've been even quicker! Great to see Schumacher qualify in 3rd too. Should be a fantastic race tomorrow.