In this video, Amanda Rigsby goes over how to make keyframes go 'backward' by going into Keyframes Assistant and clicking Time-Reverse, as well as pairing that with the Easy Ease within the Key Frames Assistant as well.
Transcript:
Since I'm new to After Effects, I didn't really dive too in-depth with this project, especially because it was our first one. But what I can show you is what I did on my picture. So I was using anchor points and the position and rotation tools to get where I wanted my picture to be. But then I copied and pasted that to get my second picture on the way down, and I reversed it.
So if you highlight and go to Keyframe Assistant, you can go Time-Reverse Keyframes, and that way, you don't have to individually try and make the same keyframe as you had on your original copy. That way, it's smooth, and you don't have to worry about it. I also, with this and the other one too, in the Keyframe Assistant, I also did Easy Ease In. That way, it looks fluid and good with the rest of the animation. So, that's what this looks like.