Both Lawrence and Linda say that the day, which is also their anniversary, is a Thursday, but when Candace holds up the calender, the date shown as their anniversary is a Tuesday.
When Phineas' camera is live on his parents which is displayed on the big screen behind the band, the crowd behind his parents is on the live (camera) shot. But on the widescreen of the whole concert, no such crowd exists behind his parents.
Mom asks Candace, why there are so many people in their street, even though she's not driving through the street, she directly drives through the garden as seen from above.