This is a short reminder to put in consistent effort throughout the last ten nights and not to slack on the even-numbered nights.
Ibn al-Qayyim رحمه الله said in Badā’i al-Fawā’id (1/55):
“If Laylat al-Qadr (The Night of Decree) was some night during the entire year, I would stand in night prayer the entire year to get it. So what do you suppose should be done for merely ten nights?”
Just ten.