In timeline mode, find the photo; you may have to scroll vertically if it is on a high numbered track. Click on it.
Click on the Effects tab, movement effects, Siz/Position. Make sure that the button says Preview and not Edit. You should now see a dashed line around your image. If there are key frames, click on the first one and then move the image down to where you want. Click on the next key frame and do the same, etc.until you have what you want. Play it back to see if it works. Sometimes key frames are hidden. See the recent thread about this under the Forum tab, MEP, about changing photo length. We talk about hidden kf's in the first few replies.