Displaying Gaussian Source

[10UAikawa]

I was plotting my structure to visualize it. I set the size of my source in X and Y to correspond with the size of my unit cell for my metamaterial. However, the way that it is display the source in Vispy shows the rectangular shape of the source along the Z-direction? Why is this? Plus, it is showing that it is extending through the PML on top. Shouldn't the source exist in the X-Y plane?

Here is the code for my source:

#setting up the source 
sources = [
    mp.Source(
        mp.GaussianSource(freq_intrest, fwidth=df),
        component=mp.Ez,
        center=mp.Vector3(0,0, source_loc ),  
        size=mp.Vector3(X_size, Y_size, 0),
    )
]

The red is my source: