Trigrams are deep kung fu knowledge, so...not suitable for Saturday afternoon. That said,
I spent the afternoon researching the history of southern staff forms (Shahar, Judkins), I have a whole set of notes outlined specific to Wing Chun, so the basic transmission of material from old Song dynasty military drills, through Shaolin Temple, and later to Ming Dynasty and later on Red Opera boats is a little clearer.
The staff (spear) forms came into the Wing Chun families via just a handful of routes (a few key real and Shaolin-trained legendary figures), but by the time Ip Man learned (some of) Wing Chun, they had become unmistakably southern (the single ended long staff as boat oar) but he (according to certain gossip) would only teach them for huge sums of money. While I don't buy into that sort of talk lightly, Ip Man was an opium addict for some time, so the idea of him fleecing students for cash and giving them substandard staff training doesn't seem far fetched. You could, at the same time, get singled ended staff training in other southern schools.
However, the good news is that a common webwork of the 5B8T form connects several arts The Yang family staff forms (northern Han) contained just a handful (about six and a half...) of key techniques, these later on circa Ming dynasty became what China now associates as Fifth Brother Eight Trigram staff, which if you know Hong Kong cinema has become immortalized with Hung Kuen flair, but is way older than that.
To Young Wing Chun, this is the "Six and a Half Point Staff" technique. That's why I find the comments like "oh this makes more sense with a weapon in your hands" enlightening. Because it's true, whether or not you're holding anything.
Sigong Kwok has a great video on this.
I have no idea what school this kid is in, but it's clearly 5B8T.
