Both Gunn and Alcock shared the same picture of the latter parked in one of those director chairs that can be found on movie and TV sets to commemorate the start of principal photography at Warner Bros. Studios Leavesden. See for yourself below, and take a close look at the S symbol on the back of the chair.

DC Studios co-head James Gunn is celebrating the beginning of filming of Supergirl, which stars Milly Alcock in the titled role. The filmmaker took to social media to share a teaser photo of Alcock as Kara Zor-El as filming starts on the superhero movie.

Thrilled to see cameras roll at Warner Bros. Studios Leavesden on Supergirl, with Craig Gillespie at the helm and the phenomenal Milly Alcock as our Kara Zor-El. Craig brings an incredible sensibility to this story, and Milly is every inch the unique #Supergirl envisioned by Tom… pic.twitter.com/za9Tr8Vryr