A life annuity is one where up front you pay $X, and for the rest of your life you get $Y at regular intervals. They're comparing what someone would pay out on a $1,000,000 life annuity.
This is different than the 4% safe withdrawal idea because you're drawing from the principal all the time not just the interest.
Companies offer this because they expect you to die long before the principal runs out and then they get to keep what's left of it. Or, maybe you live longer than that and they have to pay more than what the initial investment earned them.