"But on this Day, the believers will laugh at the deniers (of the Judgement);"
Sayyed Abbas Sadr-Ameli
So, on this Day (of Judgement) the Believers win laugh at the Unbelievers
Al-muntakhab fi tafsir al-Qur'an al-Karim
And so, today, -Day of Judgment- the situation is being reversed; it is the turn of Allah's devotees to laugh at the infidels, scorn them and hold them in disdain