Both Uses

contrast
in
Matched, by Ally Condie
(Edited)

In contrast, my mother looks flushed and angry.
p. 110.1 *

in contrast = in a comparison that shows differences
Her body makes a heavy sound when it falls, in contrast to the lightness of her eyes fluttering shut, of her dress fluttering in folds around her, of her hands fluttering open like the wings of something small.
p. 157.9

Definitions:

(1) (contrast as in: contrast their writing styles)
point to differences between; or compare to show differences
(2) (contrast as in: there is a contrast)
a difference -- especially a notable difference; or the side-x-side arrangement of things that draws attention to an unmissable difference
(3) (contrast as in: sharpen the picture contrast)
the difference between tones of an image -- as in a photo or video -- such as the quality of brightness or the intensity of shades or colors
(4) (meaning too rare to warrant focus)