Buy some chalk.
As you go through the reps, you are getting the barbell slightly too close to your shins. You can see this on the relationship between knees and elbows. Mark their position in rep 1, where you are set up correctly, and then see how your knees move back through the set. It's maybe 1/2 inch of movement, but it makes a difference and reduces the amount of knee extension you can get off the floor.
I would also like to see you pull more slack out of the barbell. Do step 4, get your chest up hard, and try to bend the barbell. You should feel 99% of the weight of the barbell in your hands and in your feet before you pull. Get your chest up hard, pause slightly, then start the deadlift by pushing your feet into the floor. Don't let your back change shape--just push your feet into the floor. You are jerking a little bit off the floor and losing some of your back extension in the first 2 inches of the pull.
Keep the barbell on your shins! As Rip says, "drag implies contact". Keeping the barbell on your shins will fix the problem of being on your toes.