The video came from:
Taiwan Apple Daily online news: http://www.appledaily.com.tw/appledaily/article/entertainment/20101002/32855910/
At 1:12, Yonghwa showed the pic when he went fishing with his dad for the first time ...
The news article has this baby pic too, but not mentioned in the video.
Yonghwa tells more about the going-fishing-with-daddy photo more in another video starting at 3:24...
He said he brought this pic because he wore an outfit of the same style to Taiwan.
The Taiwan media just like CNBLUE members' childhood photos, a magazine featured those too.
I scanned two pics from it (Fans No.71. 2010 Nov) Sorry for the poor quality, the pics on the page are small.