When collaborate with team members, reader and runner can only see the output, can not see the code

We need to share notebooks between team members and I give my colleague reader and runner permission of my notebook, but when my colleague open the notebook, the notebook is in report mode, and he can see the output of my notebook and can run all the paragraphs, but he can not see the code.
I am just wondering is this how zeppelin is deigned? or is it a bug?

The picture below mock the scenario of mine:
You could see that the owner admin share the notebook with user1 and give user1 reader and runner authority:

And when user1 open the notebook, user1 can not see the code, only the output of the paragraphs: