Nowadays, it is used only occasionally for artistic purposes or in unchanging expressions.

The general sat immobile for almost a minute, staring at the desk, his expression unchanging.

Audience members noted the unchanging expressions of the masks.

Rod stood at stiff attention while the Admiral regarded him with an unchanging expression.

Wantanabe appeared to accept their story at face value but his unchanging expression gave no clue to what he was thinking.

While behind him sat his assistant, one eyebrow raised in an unchanging expression of casual curiosity.

But Odo's silence and unchanging expression made the grin fade.

He spoke, as always, in a monotone and with an unchanging expression.

He could also recall the unchanging expression upon the face of Quarley.

Those eyes, with their unchanging expression of concentration and thinly hidden anguish, regarded him.