The reasons for? Siu Lim Tau movements?

[Fei Ze Min]

I have some questions about why we do the things in Siu Lim Tau that we do, mostly the "second part"

The motion where you have your arms crossed and that shoot out to the sides. I'm hard pressed to think this is some sort of attack if you have an opponent to the arms length and side of you....

Same question for the two hands shooting behind you. This does not seem very wing chun... What is the purpose?

Thanks friends

I like to think that tucked into the form is where we define the centerline in a multi-dimensional aspect. When we cross the hands in front first down then up, we are defining height. The two vertical punches following that are defining depth. When we get to that second part with the double knife hands to the side we are defining width. These are all the dimensions we as humans exist in (and fight in).