When exporting with a style we want to append the modules.

Instead of replacing the module's parameters in the image history
it is better to append the style module (as new instances) to be
able to adjust the current image (adding some light for example).

Until now the style during export was mostly usable when applying
a style with modules not in the developed images.
See: a83845392e33e82a700d4bdb8c9380c3b5680de6 1db2794246b132d03cd08e6e0fe0e63d56b34242