hey how what do we call this type of edit and how do we doit?is there a tutorial to do it?

Please check the above video.There is an edit pattern where the image of the video preceeding comes first and then the video. What do we call this edit and how do we do it?pls help me with this.

Yeah, easy.

Export the 1st frame of the incoming clip as a PNG
In Pixlemator (or Photoshop) crop out whatever and isolate it.
Import that newly created PNG back in FCP X.
Edit that as a connected clip above the outgoing clip.
Position, trim and keyframe it to animate as desired.

OR

Place your playhead on the first frame of the clip in the Timeline.
Right-click and Find In Event Browser.
Then Edit > Connect Freeze Frame.
Move it over the outgoing clip, trim as desired.
Put SliceX on that and mask out what you want in that clip.
Keyframe it to apply any desired animations.