This marks the first time that Paige is able to heal someone on her own.
Near the end of the episode, Rose McGowan is clearly sick when she's speaking to Henry.
After Billie threw her smoke bomb in the bank, Paige seemed to have inhaled some of the smoke and it made her temporarily nearly lose her voice for a few scenes. In the final scenes (which may have been filmed in a different order), Paige's voice returned to normal.
The "I" in the "Happy Birthday" sign is actually a "T". This is most easily visible at the beginning of the episode when Piper is talking to Wyatt.