Are emotions a function of muscle contractions? If so, how does the map look like?
Your brain mentally represents afferent bodily input as affect, or feelings of pleasantness/unpleasantness and arousal (Craig, 2002).  In certain theories (e.g., Barrett, 2017), your emotions are cognitive interpretations (conceptualizations) of your affect in a context.

In general, there is very weak evidence that discrete emotions correspond to specific and reliable bodily responses (for the most up-to-date meta-analysis, see Siegel et al., in press). 

There is also indeterminate evidence for specific and reliable correspondences with facial movements.  This has not been studied well enough to be known, although there is compelling evidence to suggest that there are no specific/reliable links on average (see Hillel Aviezer's work).

In general, emotion research is converging on the view that emotional events are highly variable, both within and across emotion categories, as well as within and across individuals and cultures. We see this variability in neural activity, physiology, behavior, hormones, vocalizations, facial movements, and so on.  From this perspective, there are no unique emotion signatures.