What are the small Rocket icons - My Study Plan

On the "My Dashboard" screen when looking at "My Study Plan" I notice that some of the lesson boxes have a small rocket icon in the upper right hand corner and some do not have this icon. These are lessons that have all been completed (or near completed) so the lesson boxes are green. The little rocket icon doesn't seem to be correlated with any level of completion. What are these icons?

Actually, what I notice is that the small rocket icon appears on the upper right hand corner for those lessons that I have completed. Also, I think every item has to be rated so-so (yellow) or higher. If anything is rated lower than that, the box will appear green but without the rocket icon.

I would have thought it was done by level of completion but I have a lesson that is farther along (by color) then others and it does not have the icon as the others do. Maybe a small system glitch?

Hi everyone, thanks for your questions and comments. The green rocket indicates that you have rated all of the phrases in that lesson, in every test. Even if some have been rated less than "It's Easy", the rocket will still appear. I hope that helps!

Good to know, Thanks