I don’t get why people are so worked up about this.
Covering at the Mitzvah tantz is a Rebbish Minhagim, not Belz. It is done in all Rebbish circles.
As a Belzer, I can assure you that no other Belzers do this, it definitely has nothing to do with Halacha.
And if someone feels they want to take an extra step in Tznius, without bothering anyone else, then good for them.
Many Minhagim is far beyond my understanding, but as long as it isn’t done on another person’s expense, I respect it.
And about the smiles,I’ve seen plenty smiles throughout this wedding. Yes, it was very serious too, considering all the emotions involved, for those who know Belz history.
Don’t dig up more problems than our communities already have. We have enough, no need to search for more.