It really is just noise, more precisely a kind of Perlin noise combined with a "color burn" blending mode. It is not dithering, though it looks like it because it is applied on a gradient.
The idea with dithering is that you start with a smooth image (high color depth) and quantize it, that is, reduce the number of colors. If you do it the simplest way, by integer division, you will get banding. To reduce banding, the idea is that for each pixel, you choose between the rounded up or rounded down value semi-randomly, with a probability depending on how close you are to each value. It will give gradients a noisy look, but if you happen to be on exactly the color you want, it will not look noisy at all. Even though dithering can be a stylistic choice, it is more often a technical one, so that you can have a good looking image with a limited palette.
Here, the effect will result in a uniformly noisy texture, and it will not reduce banding if present. I think that for aesthetic purposes, it is better than true dithering.
In addition to the aesthetic value of adding texture to the object, just like dithering, it can also improve the perceived quality of the image. For example, it can mask defects and increase the perceived sharpness.
> To reduce banding, the idea is that for each pixel, you choose between the rounded up or rounded down value semi-randomly, with a probability depending on how close you are to each value.
This oversimplifies it a bit. Most dithering algorithms are deterministic. They are based on choosing a value for a pixel, remembering the difference between the ideal and the chosen value and then spreading out that difference to surrounding pixels.
Random dithering is more commonly used in audio signals, AFAIK, not much in image processing.
The idea with dithering is that you start with a smooth image (high color depth) and quantize it, that is, reduce the number of colors. If you do it the simplest way, by integer division, you will get banding. To reduce banding, the idea is that for each pixel, you choose between the rounded up or rounded down value semi-randomly, with a probability depending on how close you are to each value. It will give gradients a noisy look, but if you happen to be on exactly the color you want, it will not look noisy at all. Even though dithering can be a stylistic choice, it is more often a technical one, so that you can have a good looking image with a limited palette.
Here, the effect will result in a uniformly noisy texture, and it will not reduce banding if present. I think that for aesthetic purposes, it is better than true dithering.
In addition to the aesthetic value of adding texture to the object, just like dithering, it can also improve the perceived quality of the image. For example, it can mask defects and increase the perceived sharpness.