In one scene, we see Lisa as a baby, but in the background, there is a photo of Lisa when she is older.
In one take of the documentary filmed on Homer's life, Bart is a toddler and Lisa's just a baby. In the back, there is part of a picture in which Bart, Lisa, and Maggie pose, even though Lisa is just a baby and Maggie hasn't been born yet.
When Homer shows his chest tattoo to Marge, the background changes between cuts even though the camera angle hasn't changed.