Firstly, the icons are scaled badly, not following android's design guidelines for notifications. Secondly, the image could maybe represent the person you are going to notify? Maybe a cool idea. Thirdly, the inbuilt countdown timer is actually a countup timer, so I've got some funky numbers going on there.
Ok, let's fix the icons. So I had a look at the official Google documentation for the status bar icons and it says 32x32 and I had a look and automatically assumed 32x32pixels, instead it's android's device pixels.
Adding an image was quite straightfoward, I went a little bit more fancy and rounded the image for effect.
Looking at Stackoverflow and other technical sites did not really help that much, so I figured I'd roll my own.
The end result for now. I've got the timer as the message text, the number of people that will be notified in the right text area, and the first person's image in the big icon area.