UC Berkeley Professor George Lakoff discusses concepts from his 2008 book, The Political Mind: Why You Can't Understand 21st-Century American Politics with an 18th-Century Brain.
"A little girl suffers an emotional wound. In her imagination the Wound takes on a life of its own, in the form of a shaggy creature that becomes her best friend. They grow up together. Firmly ensconced in the mind of the girl, the Wound starts to control her life completely."
"The conception of metaphor in cognitive linguistics contradicts the conception of metaphor in literary studies in fundamental ways: Metaphor is not a stylistic device, but an experiential and cognitive process, in which we use properties, relations, and entities that characterize one domain of experience and/or knowledge (source domain) to understand, think, plan, and talk about a second domain (target domain) that is different in kind from the first. 
According to CMT [conceptual metaphor theory], source domains come from everyday bodily perception and movement. They are grounded in embodied experience (grounding hypothesis). Source domains are needed to make sense of target domains. By definition, a conceptual metaphor is a unidirectional mapping across cognitive domains. The mappings are tightly structured and structure from a source domain is (partially) mapped onto a target domain. The mapping is highly selective, as there are ontological correspondences according to which entities in the source domain (agents, objects, trajectories and so forth) systematically correspond to entities in the target domain. The point is, that we do not copy structure from SD [source domains] to TD [target domains], but we import whole sets of knowledge / inferences / entailments from the source domain into the target domain. The mapping does not work according to an arbitrary rule, but it is a tightly packed, highly selective and constrained process that allows us to reason about abstract domains. "
(Alexandra Jandausch, 2012)
 Lakoff, George (1997): "Women, Fire, and Dangerous Things: What Categories Reveal about the Mind". Chicago: University of Chicago Press.
Jandausch, A. (2012). "Conceptual Metaphor Theory and the Conceptualization of Music". 5th International Conference of Students of Systematic Musicology. Montreal, Canada.
Fig.1. The Roy Castle Lung Cancer Foundation, Passive Smoking: Shotgun [http://adsoftheworld.com/media/print/the_roy_castle_lung_cancer_foundation_passive_smoking_shotgun].
[The source domain in the following image refers to the concept of a shotgun, which through its mapping onto the target domain of the cigarettes communicates the idea that smoking kills.]
"How do metaphors help us better understand the world? And, what makes a good metaphor? Explore these questions with writers like Langston Hughes and Carl Sandburg, who have mastered the art of bringing a scene or emotion to life."
(Jane Hirshfield and Ben Pearce, TED–Ed)
Dan "O'Hara argues that, strictly speaking, the term skeuomorphism refers only to those vestigial elements in nature or artefact that survive from an original form, even though they are no longer required. At its broadest, this definition extends to the levers and dials in a modern aircraft cockpit, for example, which no longer connect to systems directly, but instead are merely inputs and outputs of a computer that actually controls things. Such controls are skeumorphs because they are holdovers from the days before computerised aircraft, and have been left in their original form for the benefit of pilots, who are used to them working in a particular way.
So can a digital depiction of something properly be called a skeuomorph? It is more accurate to refer to it as a visual metaphor that calls to mind a physical skeuomorph without really being one. The iPhone's notification panel, with its imitation linen effect, was not descended from an object that was once made of linen. The switch that, say, allows you to switch an iPhone into Airplane Mode is not an on–screen replacement for what used to be a physical switch. In the early days of graphical user interfaces, designers employed familiar devices, such as folders, trash cans and other objects commonplace in the office. The result was that operating systems ended up being littered with depictions of things that had never existed inside a digital device; the on–screen 'trash' icon is not the vestigial remnant of an actual trash can that was once part of the computer, which is why it is really a metaphor, not a skeumorph. (That said, as computer graphics became more detailed, the original blocky icons gave way to more detailed depictions of trash cans, folders and so forth, which are arguably skeuomorphs of visual metaphors.)"
(Glenn Fleishman, 25 June 2013, The Economist)