Highlights in springer journal I have submitted a paper in springer journal which stated in the instructions for author to provide highlights in supplementary material. I forgot to provide at the time of submission and 3 days have now passed. If I email highlights to the journal now, I fear they could say my submission as inappropriate for the journal  as it is in admin processing stage. Is submitting highlights really essential for successful publication? What can be the consequences if I don't submit highlights now. 
Moreover, the journal says in instructions to send highlights in 3 page PPT. Does it mean 3 slides of powerpoint only?
Good news—the highlights are not so important that their absence will make a big difference to whether your paper goes out for review. Just wait and see what happens next. If the editor likes the work, they will request you add the highlights at a future revision stage. All that said, it is generally good to follow their instructions.