"Loose Ends": Blow-up doll
Start the mission and continue all the way until you get to the first building. Once clearing the entire first floor of enemies, make your way upstairs to breach the doors. Breach all doors on that level until you get to the last door to breach on that floor. Once you squad has announced all clear, make your way into the bathroom, which should be to the right of the room as soon as you breach it. Look into the bathtub and you can see a blow-up doll with colorful stars on its chest and a circular mouth.