She quietly observed everything around her without letting anything show.
Tips
history
From Ouyang Xiu's Song-dynasty 《相州昼锦堂记》: '垂绅正笏，不动声色，而措天下于泰山之安。' — a great minister brings the realm to the stability of Mount Tai without betraying a ripple in voice or expression.
usage
Strong positive or neutral tone — admirable composure, especially under pressure or when planning in secret. Often adverbial with 地: '不动声色地进行'. Contrast with 喜形于色 (joy shows on the face).
