картинка, рисунок, изображение
1 Answer
"Картинка" literally means "little picture". While "картина" refers to an art object, "картинка" is something not so great, but usually describes something beautiful or at least interesting. For example, "красивый, как картинка"/"красивый, как [будто сошёл] с картинки". Generally, "картинка" has positive connotation, while "рисунок" and "изображение" are more neutral.
"Рисунок" without a context commonly refers to a child drawing or rock paintings. In technical documentation, illustrations are also often called "рисунок". For example, very common technical phrase is "см. рис. 1", where "см." is for "смотри", "рис." for "рисунок". Though a technical drawing is never called "рисунок", it's "чертёж".
"Изображение" is just a 2D representation of any real world object. Though with modern technologies, it could also be 3D. This word is not so common in conversation, it sounds pretty techinical.
picture,drawingandimage.