In the Clone Wars animated series, the Twi'lek species' name was usually pronounced as "TWEE-lek." But here, when the Imperials say it, they pronounce it "TWY-lek."
Grand Admiral Thrawn mispronounces "Hera," "Syndulla," and "Twi'lek," a strange error for someone professing his desire to know the culture of his host planet. Captain Slavin similarly mispronounces Hera's first name and species, though manages to get her family name correct.