Thanks everyone, I should have been more clear and also said I ended up getting this bag:
https://www.trekbicyclesuperstore.com/product/bontrager-elite-small-seat-pack-295645-1.htm?variations=97902&gclid=EAIaIQobChMI5tr6wvbY2wIVkYZpCh3htw-eEAQYASABEgIPdvD_BwE
An iphone technically doesn't fit in it but I cut a piece of wood to size and stretched it just enough so I can get my iphone in.
The bag I posted in the OP would have been perfect if a phone could have fit in it.
Part of the issue, for me personally, is the mix of aesthetics vs. functionality and a few other parameters in deciding on a bag and pretty much everything else in life. I'm sort of a particular person and after getting fitted to the bike, needing new cranks, I spent twice what I needed to with a 75/25 split between aesthetics and weight savings. The benefit being they look fantastic on the bike and make me want to ride it more. Which I do so money well spent.
My question was more, would the case I thought of, sell. Probably not but it was fun to think about while riding yesterday. The vision was the Zero Halliburton of bike bags.