Now that I’ve gone and checked. It’s just that the hand looks lower down than in should be compared to Java in first person.

To reproduce:
Join a world making sure you’re in first person. Now look at the hand.

As you can see in the images uploaded below. The one with the arm lower down is what it currently looks like, and the other is what it should look like (fixed with a resource pack).

Also, I only know that this is true for iOS, Android & Windows. I don’t have the ability to check others.