A tube of lipstick is the title image of episode 1.15 "Queen Sacrifice".

On Thursday, April 29, 2010, the lipstick was used by someone to write the QED formula on Olivia Benford's bedroom mirror. It was originally thought that the writer was Lloyd Simcoe. After Simcoe left the room, Benford spotted the tube of lipstick on the carpet and picked it up. ("Queen Sacrifice")

When the day actually came, it was revealed that it was not Lloyd, but his son Dylan Simcoe, who used the lipstick to write the formula on the mirror. ("Future Shock")