Yes. Here's one way to do it. I'm using a cone, rather than a pyramid, but the solution is the same.
How To
Camera
- Add a camera at the origin
- Clear the rotation of the camera so that it is pointing straight down.
- Move the camera on the Z axis until the entire base of the cone is visible.
Slicer
- Add a plane at the origin
- Rotate it 180 degrees on the X axis in object mode.
- Apply the rotation.
- Go to Object Properties and in the Viewport Display panel set Display as to wire
- In the outliner disable render for the plane.
Object
- Add the cone at the origin.
- Add a Boolean modifier to the cone.
- Set the Object field of the modifier to the plane.
- Set the type to Difference but see below
You will end up with something like this:

and the view from the camera will look like this:

The outliner should look like this:

and the modifier like this:

You can animate this by moving the plane to just above the base of the cone and setting a keyframe on the plane's location at frame 1. Then move to whatever frame you want the full reveal on, move the plane to just above the cone and set a keyframe on the frame's location.
But you wanted to reveal just the area at the cut. To do this switch the Boolean from Difference to Intersect
Things To Watch Out For
You'll have to scale your plane so that it's larger than the largest slice of your object.
You may have to switch to the Fast Solver if the Boolean gives you trouble.
How It Works
The plane is set to wire display. This is a common technique when using a non-destructive Boolean workflow. It allows you to see the position of the plane without it obstructing your view of the object.
The plane, of course, shouldn't appear in final render, so disable that in the outliner.
The plane is rotated so that the desired part of the cone is revealed. You can also accomplish this by flipping normals in the plane but rotation is easier to describe.
The Boolean does the heavy lifting.
The plane's movement matches your need.