The best word to describe Séraphine's frame is simply "tiny."  Stock phrases like "dancer’s body" or "runner’s physique" that some women employ to suggest an efficiently compact frame don’t seem to apply to her; even "petite" doesn't really convey the full sense of her lack of stature.  Though in her late 20s she might not have gained a single inch of altitude since she was twelve: she could at best be generously described as "willowy," if one were to overlook that she stands all of exactly five foot one.  She looks like she could scarcely stand up to an enthusiastic gust of breeze, to say nothing of taking a punch; the idea of her holding her own in anything resembling a fight seems flatly ridiculous.

In superficial appearance, some sort of heritage that 1920s Americans would probably simply categorize as "foreign" is apparent in her gently dusky bronze skin, shiny coffee-brown hair, and amber eyes which, if caught at just the right angle in just the right hue of light, seem to spark golden.  Beyond that, any specific ethnicity is hard to pin down simply from looking at her: she might hail from Greece, Spain, Brazil, North Africa, India, Mexico, Arabia, Cuba, some combination of any or all of the above.  Delicate, very feminine features and high cheekbones and full pouty lips afford her a charming presentation but do nothing to counter her overall aura of being a flimsy little slip of a woman.

Being physically unimposing does not, however, keep her from having a bit of metaphorical weight to throw around.  Her presence is intensely magnetic, wildly out of proportion to the physical space she occupies: it fills up rooms, dominates conversations, and demands attention.  Her voice is a sultry, smoky alto which when speaking English (or most of the other tongues she's fluent in) carries an accent as French as her name.  She's commonly bedecked in what might be stereotyped as a gypsy's outfit, lots of wispy brightly colored silk and generous spanglings of gold and sparkly gemstones at her ears and throat and wrists and more than half of her fingers and occasionally an ankle or a toe.  Always, always present on a sturdy braided leather cord around her neck is a gold pendant set with an odd, strikingly iridescent blue-purple cat's-eye stone the size of a half-dollar coin.