Use the Event Pan/Crop window to move around your pictures. If you use track motion, everything on that track is gonna move together... Or, if you still wanna use track motion for a wider range of motion, then have only that one image on the track.
However the new Picture in Picture filter makes this whole process a lot easier.
As @Steve_Rhoden suggests, tracks are cheap. However, your track headers are not wide enough are not wide enough to expose the track motion buttons, so we don't even know which track you are refering to.
@winas-ben If you really need to use track motion instead of Event Pan/Crop, you need to place reset keyframes at the start and end of every event. The events will the move independent of each other. Make sure you place the 'end event' reset keyframe one frame back from the event boundary. This will make sure that, if you need to move your event, all the keyframes will move with it.