Irene had found out early that her credit cards still had worth here. Inside the casino, she had no use for it -- everything was complimentary -- but outside the box was where she lived. She'd secured a dress, chosen specifically because it flattered her in all the ways she knew that Sherlock admired (or would admire) and had her hair styled and down for the occasion. Post resurrection softness might be needed, at least temporarily before she smacked the living daylights out of him for doing that to her.
(Never mind that she was clearly a hypocrite.)
Irene stepped into the restaurant in a long fur coat, the one truly opulent thing about her appearance. The host moved forward to take her coat. Irene caught his eye just long enough to make him blush with the dirty little smile on her face. It didn't appear that she'd noticed Sherlock in the least, but as she turned away, she strode directly to his table without another word.