The white arrowed lines on MSO document seem to be missing in Impress.
Created attachment 153946 [details]
Created attachment 153947 [details]
Document opened in Impress
Created attachment 153948 [details]
Document opened in MSO
*** Bug 127387 has been marked as a duplicate of this bug. ***
Those are drop lines, something we don't support yet.
*** This bug has been marked as a duplicate of bug 77131 ***