What is the function of allatī taṭṭaliʿu ʿalā l-afʾidah?

Supplementary Practice 20: Comparative Rhetorical Study of Sūrat al-Humazah and al-Fīl

• Further describing the fire and its effect
• The relative pronoun serving as an independent conditional apodosis
• Treating it as full substitution for wayl in verse 1
• A genuine interrogative unrelated to the description of fire