How is this font displaying the same letter in different forms?

Question

I'm using a font that displays letters in a random way (not limited to uppercase and lowercase) and I'm not able to understand why.

In the following images, the same uppercase G is rendered differently at different positions:

Try it yourself here. (select the web font variant)

I'm using Ubuntu and I tested it on Firefox and Chromium. In fact, the same behavior occurs in LibreOffice Write (after installing the font locally).

How is this done?

Answer 1

This is an Open Type feature called Random Contextual Alternates:

Random contextual alternates provide multiple substitute glyphs for a single character. When implemented with script-type fonts, this feature can simulate handwriting by using of a set of randomly chosen glyphs with slight differences in appearance.

Open Type comes with features such as contextual ligatures, and stylistic sets. If you look at the font's OT version's details on the page you posted you'll see all of the features it uses.