Having stripped and tied up the guards and emptied the vault's security boxes, the robbers decided to "take advantage of the situation" before leaving.
The blonde guard has a look of defiance on her face. While the brunette guard looks like she has given in and is accepting what is happening. Perhaps she is even getting ready to let herself get turned on by what is happening.
The look on the blonde thief's face is also really cool. She is clearly enjoying toying with her lovely prisoner.