The aquarium has a resident. The resident has landscaping.
At first, the plants do most of the appearing in our short clip. Leaves fill the view, the eye follows one gap and then another, and the small blue fish takes its time entering the conversation. The tank looks less like an empty room and more like a house where somebody has declined to answer the door.
A very small search party
Try watching the first few seconds without following the camera. Pick one opening between the leaves and look for a change there. Then widen your view. The fun is in the difference between knowing a fish is present and actually finding it.
This makes a good little guessing game with someone beside you. Let them find the resident before you point. The reveal lasts longer when nobody shouts the answer immediately.
The plants get a supporting role
We usually describe an aquarium by its fish. In this scene, the leaves set up the whole joke. They give the fish places to disappear from our view and give us several very convincing wrong places to look.
Eventually, there is an appearance. No dramatic entrance, no apology for the wait. Just a small resident moving through a place that seems to be working quite well for it.
The privacy policy is mostly plants.