Why are there two ways to keyframe-animate geometric transformations?
The video transform tools in the edit page inspector window (zoom, position, etc) actually translate directly to the color page in the "Edit Sizing" window.  In your screenshot your color page is showing the input sizing window, which instructs resolve how to scale the image as part of the input process (very front end of the image processing pipeline).  If you place your mouse over the Input Sizing menu item, you'll see that there is also edit sizing (inspector on edit page), node sizing (associated specifically with the node you have selected in the color page), output sizing (how things get sent to video monitors), and reference sizing (lets you reposition/scale an image when using the wipe function to compare two clips in the color page).