When Alli is alone in the apartment and watching the neighbors, the binoculars are visible on the window sill, but when she wants to use them, suddenly they are in a desk drawer.
The children have not grown in almost one year (from before Christmas until around or after Halloween).
The distance/angle of the hinges between the two parts of the binoculars when Alli watches the neighbors, puts them down to get the dry cleaning and picks them up again.
When Alli looks outside on her balcony, the last second of the footage appears to be reversed. It is most notable with the highway in the background.
The neighbors never spot the protagonists watching them: no matter they care or not, they should have noticed the staring and watching.