[spaky]

(I am also a dev for Dango)

This is definitely a concern and something we've though about but not yet fully solved. The neural net is trained on real world data which unfortunately includes various types of questionable, racist, sexist, etc content. We already blacklisted emoji combination that are too often triggered in racist ways. However such a system is very difficult to audit completely.

Your example comparing different skin tone modifiers is a good one that we hadn't thought of. I've made a note of it so we can try and improve.