Help resizing an image without changing previous frames!

I drew up an image in Photoshop. I imported and vectorized the image, what I’m trying to do is resize it on one frame without resizing the rest. I tried adding a keyframe - didn’t work. I tried inserting a keyframe and duplicating the drawing - didn’t work. What am I doing wrong?

Ok hook up your drawing layer to a peg layer, now make sure your animate button is engaged, its in your toolbar, add your first keyframe, then add your last keyframe, go to first keyframe and hit shift+, that extends the exposure of your first keyframe by one frame. in the middle you have a new frame, add a keyframe there. In the peg layer resize your image. when you scrub through the timeline. you should see your image resize and then go back to its original size if you want a smooth transition to and from, extend your exposure by 10 frames on both sides, then tween using the tween button, that button is located in the timeline view menu bar its called the set motion keyframe button, its right next to the add keyframe button. Give it a shot and let me know.