Girl group Girls' Generation's Yoona filming for a commercial was revealed.

Recently in an online community forum, pictures were posted under 'Yoona who cracked up in the middle of filming for a photo shoot.'

The pictures were when Yoona and Jang Keun Suk were filming for a commercial. Yoona is wearing a long black dress, and she suddenly bursts into laughter, and cannot stop that she falls on the ground.

Jang Geun Suk, who was looking at her, also could not hold in his laughter, bringing curiosity to those who saw the pictures.

Internet users who saw this commented, "Yoona's pretty even when she's cracking up" and "They're such a cute couple."

Photo Credit: Online Community