Ionic Push sent data



I used to understand how things work.
I managed to use gcm services in the end. Now i can send push notifications from my command line to my device.

The only thing i couldn’t understand is where responsible bit of code is, that handles to prompt text-message from user.
After understanding that, i want to be able to send images from the device instead of sending alert messages from command line.

I couldn’t manage to find in docs.

Any Help?