As for this picture of Ip Man, notice his single leg stance. Look at the alignment of the upper thighs to the calf, as if the lower leg is simply hanging from the knee. Then, if you look closer at the foot itself, I call this Poon Long Gerk (enclosed Dragon foot)
This posture is very very famous in Canton Opera, and fundamental to all legwork training. And to share a little idea with you all, I have used such positioning on the Wooden Man to 'leap' up onto the arms then head of the wooden body where I settle into a single leg stance to practise SLT!!!
Not recommended for everybody, but something that you would experience if you learnt any Lion Dancing or Mui Faa pole stepping combinations. Both of which I was exposed to a little during my time learning Wing Chun at Jun Mo.