1. Both are (or were) ennormously popular.
2. They both are known for portability. Although you couldn't keep a Brownie in your pocket it could be easily carried around...especially if you compare it to the view cameras that it replaced.
3. They are both very simple to use. You took a picture with a Brownie by looking down into the finder and clicking a button.
4. They both became the de facto leader in the field. Apple dominates just as Kodak did.
5. Simplicity defines both cameras.
6. Unfortunately, the Brownie only let you take a dozen or so pictures per roll. Of course the iPhone lets you take a few (thousand) more.
7. Although you could alter the photos in the darkroom with the Brownie, the iPhone lets you do everything on the spot.
One final comparison, the Brownie cost under ten bucks!
[Incidentally, if you still want to use a Brownie, you can. You will need to re-spool 120 film onto 620 spools. Not easy, but possible. Incidentally, the Brownie Hawkeye did not come with the red that you see in mine. It was modified by Randy Smith of Holgamods.]