Same as my short haul carry on...
'Cept...

More snack foods!

I don't add other items. I probably pack a sandwich or fruit if I'm going longer than 4 hours via air without connecting.

My short haul bag has my Color Nook, headphones, eye mask for sleeping, laptop, emergency meds and toiletries, earplugs, hand sanitizer, water. Long haul, as per above, adds food.