NFL teams ask their players to attack the ball in the air, to catch it with their hands, high and low point the ball and make hands catches, rather than let it come into their chest. They ask QB's to the ball where only the receiver can make a play on it, to minimise risk, so being able to snatch the ball out of the air, in stride, high or low is important.
NFL Db's are usually playing too tight coverage, so if you let the ball come into your chest, you give them a greater chance to be able to swat the ball away, rip it out once it gets there or worse, under cut the route and pick the ball off themselves.
If the balls thrown at the numbers (that refers to the numbers on his jerseys, ie thrown at his chest), they still want you to be extending your arms and attacking the ball, then tuck it away and secure the ball, not let it come into you and secure it that way
Hayne has been playing all his life in a code where you are taught the let the ball hit your chest to catch it and the clip showed he still has that tendency to let the ball come to him