Thanks Eliza that's most inciteful:

"The costumes and movements actually remind me of those tin automaton wind-up monkeys dressed as black men and wearing a fez, with a coconut shell in each hand."

Such music hall acts and related activities mocked black people - and that lies at the root of the concern that some of us have.

And as for:

"The dance is really very funny, and to my eyes not in the least 'traditional'"

If the 'serious' BCND defenders read this you may have to join a witness protection scheme.