When Jimmy's sneaking out, the picture of the family is hanging on the wall, perfectly straight, halfway up the stairs and with three other pictures surrounding it. The next morning, it has moved to the top of the stairs, is slightly crooked, and the three pictures are gone. The next time it's seen, when Jimmy looks at the picture while walking up the stairs the next day, it's back in its original position and the three pictures are around it again.
When the kids first see their parents again they are circled around the giant hatching chicken. The camera cuts away and in the next shot where the chicken is visible, the parents are missing. They return a few shots later.
In the beginning of the movie, jimmy uses yarn from Carl's sweater, which becomes visibly shorter. However, in later scenes, when Carl is hanging from a tree, his sweater is back to its initial length.