It's difficult to determine an exact line that can be drawn between discrete symbolism and ostentatious declaration, and I imagine this is an attempt to do just that. It doesn't matter where the line is drawn, there will always be those that seek to bend it to their own preference.
The whole concept of religious symbolism, whether as magic underwear, crucifix or niqab, is one that raises emotional objection, as it emphasises the tribal attitudes that generate negative competitive responses.
It might be more straightforward to set guidelines based on facial recognition ability along with practical (non-dangling) restrictions if that's what they are trying to achieve. When France banned the facial veils, it was thought that there would be a huge backlash from the Muslim contingent and yet there appear not to have been any significant repercussions.
If you are an angry person, you will find something to be angry about. Clothing and decorative symbolism are an easy target as they are so evidently visible, but take those away, and there will be some other target found, because anger needs a target to manifest itself.
Add the top three to the bottom three and I'm on board.
Looks like they're just trying to limit you to small, tasteful religious symbols. So -- noodle in your lapel, okay. Colander on your head, not okay.
If clothing or jewelry doesn't interfere with identification of an individual I don't understand the objection. The use of religious symbolism is more an annoyance for me personally. But if wearing a burka prevents me as a security officer from making positive ID then we have a problem.