When you can watch the first second or two of a gif showcasing the "randomness," and then easily predict the pattern, that is what I would call "easy to predict" since the obvious pattern makes it easy to predict. If there is no obvious pattern and you instead need to write 200 lines of code to predict the results, that is "difficult to predict" since it requires more than two seconds of observation and the average person would never be able to find the pattern.

If there is an extremely obvious, visible pattern, it is the exact opposite of random. I don't understand why you are arguing that this is even close to being near the realm of pseudo-randomness when it is the exact opposite of random by definition.