There's something very hypnotic about rhythm. Most have probably noticed rocking backwards and forwards as a calming behavior in themselves or others.
Music is another one, and has obvious affects on the emotional state, whether played heavy, fast, or slow.
In fact all things seem to 'breathe' or have a natural rhythm if you pay attention.
In humans, walking is an age old form of meditation - step step step step. Bagua circle walking is just another version of this. (Flow can be too.)
So rhythm and trance ... age old ways to alter state.
Trance can be good. Great stuff can come out from getting absorbed in the beat, not 'thinking' for one.
Constant editing and chatter often impede free movement, so changing states can help a great deal to find this 'natural' way.
Trance also has a calming affect on the mind - it's great stress relief.
On the other hand .... trance can also be addictive, you must watch yourself, and especially those that you teach that trance, as stagnation and addiction, has not overtaken practice.
Trance is cool, but it's nice to have a choice as to whether you want to stay with it or not.
Big sign that you, or others, are hypnotized and stuck (easier to notice in others) - You/they can't vary their walking speed ... Even if prompted to do so, it either does not change at all, or it briefly changes and the original speed returns almost immediately. This one, same, unmodulated speed pervades everything.
I like how Yizong structures training, alternating precision with smoothness, slow with fast, loose with controlled, and often begins and ends practice with unfocused 'walking in the park'. The goal is not one thing all the time, and in fact encourages playing with opposite ideas.
Cool the emotions, relax, smile, focus the mind, yes, but remember that trance loves the repetitive and continuous, so also remember to keep the aliveness and flexibility (mental and physical) that change brings with it, because Bagua after all, at it's root, is ALL about change.