(Backround) 3rd person view lets you look at yourself from a distance. However if you put a solid block between you and the "camera," the camera will zoom towards you so that it's view is not obstructed. If you get up against a solid block, the camera will get so close to you that you cannot see. This works as intended.
The problem is that barriers (in their hidden form) are invisible blocks that will trigger the "camera" to zoom up close to you. I think that this is a mistake.
How to repeat:
1. Join a creative world in first person and then make a box out of barriers that is the minimum size for the player to fit inside (1x1x2 blocks).
2. Get inside the box and seal any holes. Stop holding the barriers so that they they turn invisible.
3. Change to third person view (back or front). The "camera" should zoom into the box.
Linked issues
Comments 1

Thank you for your report!
We're tracking this issue in MCPE-128597, so this ticket is being resolved and linked as a duplicate.
If you would like to add a vote and any extra information to the main ticket it would be appreciated.
If you haven't already, you might like to make use of the search feature to see if the issue has already been mentioned.
Quick Links:
📓 Bug Tracker Guidelines – 💬 Community Support – 📧 Mojang Support
📓 Project Summary – ✍️ Feedback and Suggestions – 📖 Game Wiki