In the opening scenes, when the zombie is attempting to drink from a milk carton, it is the modern type with the screw-on cap. In 1990, when the scene is set, that type had not yet hit the market. It would have had a folding spout.
When Emily searches the house for the strange noise right before being surprised by her brother, she crosses the living room. A cameraman is visible in the large wall mirror for the entire tracking shot.
When Laura and Howard are making love near a mirror, you can briefly see the reflection of a hand on the lower right side of the mirror. It makes a quick movement which looks like a "go ahead fast" sign.