If you have a Shulker Box of any color in an inventory (creative inventory or survival, or a chest), and then look at a Shulker such that the shulker is in your field of view, the Shulker Box in your hotbar will appear to open when the Shulker opens. This occurs even if line of sight to the Shulker is blocked by solid blocks.

If the Shulker is not in your field of view, Shulker Box icons in an inventory will not open even if the Shulker does, but if you look away from the Shulker while the Shulker Box icon is showing an open box, the boxes in the hotbar will be frozen in that state until you look at the Shulker (at which point boxes in the inventory will "sync" to the state of the Shulker.) The same goes for moving such that the Shulker comes into your field of view while it is open - all boxes will instantly appear to be open.

If you switch to Survival and the Shulker fully opens to attack, the Shulker boxes in the inventory will likewise show the "twisting" opening animation of the Shulker

Steps to reproduce:

1. Enter Creative Mode
2. Put a one or more Shulker Boxes in your inventory
3. Spawn a Shulker with a spawn egg
4. Keep the Shulker in your field of view until it opens. The shulker boxes in your inventory should show a partial opening animation.
5. Enter Survival and allow the Shulker to attack. The shulker boxes in your inventory should show the full opening animation.