Blaise’s section focused on controlling one’s pain tolerance. He showed Hermione all the different pressure points on her hand that she could press into to dull any physical pain. It was an old trick his mother had taught him, and while it may have been a placebo effect of sorts, she was happy that he shared. If Hermione’s blood was to be taken, it would not be in a caring manner, and she needed to swallow the pain and maintain sharpness - observing every move of those present.