Zook you demi-god you.
Thank you for asking cuz now I have an excuse to answer!
A goat milker is a machine used for milking goats! Good news is that they work on women too. As it turns out they actually make rather poor breast pumps because they are not made for us but the good news is they can also be tons of fun. Hucows practically made them mainstream (well, OUR mainstream anyway).
If you look at the pic of Katie below you will see that goatmilkers have two sets of suction lines instead of the customary one set you have on conventional breast pumps. The lines that mount on the sides of the cylinders, there provide constant suction to keep them attached and the larger black hoses at the base of the cylinders provide primary suction that does the actual milking.
THAT model is actually a cow milkier on account of having four cylinders instead of two but they are largely the same otherwise.
The good models have adjustments for the degree of retention secondary suction as well as setting the strength and speed of the milking cycles. I live in a very rural / agrarian area so I was able to get a gently used model for about $300 USD. For some reason cow milkers tend to be WAY more expensive which is just as well because we don't have girls with four breasts... yet.
In my limited experience about a third of women get nothing out of being hooked up to a goatmilker but it is still total fun to see the looks on their faces when you roll the thing out. About a third hate it and the last third think it is some degree of fun.
At length, getting back to the actual topic, the .gif I referenced above was a goatmilker working Nadine's udders that also set up this 'motion of the ocean' wave effect and she at least appears to be enjoying the effect. BUT is is owned by "YOU KNOW WHO" and I can never post or link to it here. With a little imagination you can get a pretty good mental image, though.
PS: keep up the great work here, Zook, please don't ever change.
PPS: mad respect to Nadine. I know she has been 'working' all of these years but I still get the impression that she has been having some fun doing it as well and I am so grateful for all of her content. I wish her well.