When your number of heart is reduced (like to 2 heart/4pv) with a the maxHealth modifier,that you have 20pv and that you apply an instant damage effect on you that would not kill you when full health, but will kill you with your reduced number of health, it will show up the death screen, but if you click on respawn you will be if you not died but you will be having the death animation.

How to recreate(can have other variants):

-Get an item that has a maxHealth -13 modifier
-"activate" the item (by holding it, wearing it, etc.)
-Do /effect @p minecraft:instant_damage 1 1
-Click on respawn
-Activate third person view