The character Yu in the picture you posted is traditional Chinese, but it is a deformation of traditional Chinese. Many Chinese characters have the character "山" next to them. When calligraphers write, they usually put the character "山" on top of the characters instead of "山". On the left, this is what the calligrapher considers to be beautiful.
It is a coincidence that the first two characters do not have traditional Chinese characters. Traditional Chinese characters are themselves. For the traditional characters of Yu, please see the link (Baidu does not display traditional characters): /zd/zi/ZdicE5ZdicB1ZdicBF.htm