Probably, an app that applies some random distortion to your source image, just like your own recaptcha. Also Adverisal Patch is a thing, so that could be appl

Probably, an app that applies some random distortion to your source image, just like your own recaptcha. Also Adverisal Patch is a thing, so that could be applied to specifically distorted the system in a human invisible way to misguide the machine learning models. Whether it will be retroactively deleted, it think there is a possibility. If WeChat periodically scan your image and find your image violating the censorship, it will probably delete it and report to the authority. Again, some encryption needs to apply in this case. Just like in the old days.