Please, take no offense @Smithy but my local burrito joints, and even a national one like Chipotle, would be crying at those burritos - all of mine would put a LOT more filling in each one. They add enough filling so that you can just barely close the burrito.
One thing that helps is to either heat the tortilla on a flattop or briefly steam it - it will make it a lot more flexible and easy to handle. Similar to when wrapping something in a banana leaf, the leaf is commonly passed over a gas flame or burner.
ETA - also, one can't undersell the importance of experience and muscle memory. Obviously, people who make 100 burritos a day will be a lot better at it than someone who does it on occasion.
