The principle by which classes of windows receive their properties "from different sides of the family" is called multiple inheritance.
An Info Box (class), indicated by a fat dot, inherits its properties from two superclasses:
Horizontally, an info box (class) inherits content, look, and feel. Vertically, a (class) inherits look and feel.
This multiple inheritance mechanism may cause conflicts when contradicting look and feel properties are inherited from both parents. In such situations, USoft Developer will be the judge.