"GOOD OLD SHORTY!" Della Wharton had watched from one of the windows of her room in the hotel.

She had seen Lawler and Shorty ride down the street to Warden's office; she had seen Shorty come out carrying Lawler; and she heard Shorty's steps on the stairs as he brought his burden up, preceded by the proprietor.
She was standing in the hall when the proprietor and Shorty reached the upper landing, and when the proprietor looked inquiringly at her she silently motioned toward her room, and stood aside as Shorty entered and placed his limp burden upon the bed.

Lawler was unconscious and ghastly pale.
Della instantly took charge of Lawler.

Which means that she set seriously to work with him, while Shorty stood by, his arms folded over his huge chest, one hand caressing his chin, grimly watching.
Shorty continued to watch.

For many days he stood guard over his "boss"-- a somber, brooding figure, silent, imperturbable.