Rate Stretch clip in Editor - not in Comp reflected -why?

Hello,

the clip in editor has 3 images - frames which I cut from a longer image sequence in the editor.

furthermore I stretched this 3 frames to a duration of 15 seconds in the editor with the rate stretch tool.

Now I want to keyframe some zoom an panning effect in a comp shot. So I click the CTRL-M in the timeline using take properties from editor and move effects with clip.

but now the compshot does contain frames further behind  than the cut I took earlier in the editor.

Any idea why?