IMO, from an inexpert but experiential position, I'd suggest that simply getting the mind to do something 'neutral' while attending to something stressful defangs it. I find other similar methods have many more bodymind benefits.
You can reroute neural pathways without going into specific memories. There is a arguably a placebo or 'narrative' effect for the person who gets the opportunity to believe that they have conquered the past, when in effect they have simply used the past as an object of concentration while they discipline the mind with another object. It will change the experience of all manner of stressors.
I personally think the experience is more important that whether or not the anxious mental contents that form around the experience are objectified as memory. It is striking that the emphasis is on the visual, because vision is the least somatic of senses. Most of the response to stress is also observable through other senses that are less obvious or 'gross'. Your question reminds me of all the hokum that people pass off as healing, but is merely breathwork with a bunch of 'rituals' or 'science' surrounding it.
Most methods may be superior to talk therapy, because talk requires a listener, not self management or a 'cure'. Most people in talk therapy don't really ever get out of it. They just distribute the talk. DBT is probably the reconciliation of the talk/CBT models, an alternative.
From Crowie's link
EMDR proponents have invoked a dizzying array of explanations for the apparent effectiveness of the lateral eye movements: distraction, relaxation, synchronization of the brain’s two hemispheres, and simulation of the eye movements of rapid eye movement (REM) sleep have all emerged as candidates.
This is kind of ridiculous. It's (very) simple concentration(which can attend the relaxation response). Other labs/cultures have already covered this. It just isn't novel if you don't dress it up right. Which is a problem if you are in research.
See also, yogini Onion,
drishti.
See also, scholar Onion, Mauss,
Techniques du corps.