You do have an interesting point. I have witnessed this type of behavior before with my own observations. What is coined "Uncinus spaghetti" (curly chemtrail) - what is odd is that the same vortex wake from one engine theoretically should be very similar to the mating one on the opposite side - or one would think (as shown in the pics below) Recent attempts to legitimize this 'new' phenomenon that are becoming commonplace with these so called normally occurring "persistent contrails" has been propped up with older research referred to as the "Crow Instability" dug up from a 1970 publication by the author S.C. Crow. Yes, it is 100% contrail science, undisputed.

Wiki Crow Instability

However, either the stratosphere has contracted (not likely) in combination with a significant increase in H2o saturation - that all of a sudden we now find our good friends at Wikipedia scrambling to explain away why all of a sudden, in the past 20 years, it is now a VISIBLE phenomenon to people on the ground where as Crows experiments required tracer elements of lead to "smoke out" the vortices for study and other lab testing was done in fluids. - something that Wikipedia fails to mention.



What you have here in your pictures begs the question: What causes two very different plumes to occur from the same craft?

Engine fault? not likely as it would sputter out the same type of plume, only with intermittent breaks showing up.

Engine speed? not likely as it would probably be inefficient at flight and the other engine's wake would also affect or destroy the Uncinus spaghetti appearance of the other plume. (as we notice only one defined strand rather than two - very odd.)

An imbalance unintentionally set in during the injection of cloud condensation nuclei (additional particulate matter during vaporization stage)or coagulation/over saturation during the release of "whatever it may be", compared to the non-coagulation occurring in the other engine seems more likely.
Would be great to get an in flight sample of one of these plumes. Due to the juicy appearance alone it would suggest over saturation of some form of ccn and not just water vapor and ice crystals. In fact I would go so far as to say it could also be a potential source for the failed polymer cobweb type filaments that people report floating down after spraying?