userPresets package is smaller than the one I copied into the game folder

I hope Ciane from the Exchange can answer a question for me. If anyone else knows, you are welcome to join the discussion.

I downloaded the Ode to MrHawk n Bily lot which Ciane created and uploaded to the Exchange on 1/21/16. I saved every item on the lot individually, to unlock other stencils for different buy/build objects. When I was finished, my userPresets package file was 944,359 bytes (about 923KB). I copied this file to a folder on my desktop.

I created a new game folder, installed my store content - everything available in the store plus some other exclusive content, and then copied the file to the newly created The Sims 3 folder. Next, I installed about 40 custom content items (worlds, lots, clothing, and patterns). Once everything was installed, I quit the game running in the background and closed the Launcher. When I looked at the userPresets package in my completed The Sims 3 folder, it was 586,994 bytes (about 574KB). I opened the Launcher and the game to the save selection screen many times during the installation process, which took about two days.

Is it normal for this file to shrink when you run the game?

Should I copy the backup userPresets file over the current one, or will it do the same thing?

This is not an EA technical question about The Sims 3, so I put it in General Discussion.