Having killed a large number your soldiers in battle the son of Dhritarashtra looks highly delighted as if he believes that the Pandavas have been defeated.
हत्वा तव बलं सर्वं संग्रामे धृतराष्ट्रजः। जितान् पाण्डुसुतान् मत्वा रूपं धारयते महत्॥