Hmm, my decades of clicking things lead me to assume a flow from top to bottom, so something with a connector on the bottom is a source that will output data through that connector, and something with a connector on the top is a sink that will accept input data through that connector.

It flows in the reverse direction of what I’d expect (out is at the top, in is at the bottom, the opposite of any visual programming or diagram I’ve ever seen). It’s also represented in a way I’ve personally never seen ANN’s drawn. I thought you had to connect the dots in the middle and thought “huh? It mustn’t work on mobile” until I read the comments and tried again. And this is with decades of clicking things domain knowledge, and a small bit of neural networks knowledge.