You may have been looking for the real life star Heather Small who made a celebrity appearance.
Heather Small is the name of a real-life singer whose cardboard cut-out face was stuck to stick, and is used to motivate Miranda and Stevie in the joke shop. She is constantly withdrawn from the counter with the accompanying singing from Stevie.
During 'The Perfect Christmas' Stevie puts tinsel around the cut-out to make it more festive TBA
Stevie met the real Heather Small and they both debated how the song "Proud" should really be sung.