Hopefully someone from Readmill is around to satisfy my curiosity - why would someone raise an eyebrow at that?

When I commuted into and around NYC, reading on a larger-than-phone device was always totally unremarkable, so I'm confused. There's probably a cultural difference here that's interesting.

In Chicago it may depend on which form of transportation that you're riding. On the Metra, it's second nature to see laptops, tablets, kindles, etc. On the El, coworkers have shared that tablets aren't as common (mentioning theft) and people can be apprehensive to flashing their smartphone. I'm aware that's a major blanket statement but my experience is that ride duration, available seating, and rider demographics play a role.

Toronto reporting... iPads and tablets on the subway are 100% normal and unremarkable here.

I've noticed this is quite common here in the UK. A few disgruntled looks are fired your way if you take out/use a tablet on the train. No idea why.

My issue was the sentence: "Luckily, we have great reading devices in our pockets: our phones."

My phone is not a great reading device. Far too small. I do have ebooks on my smartphone in case I ever needed something to read, but the compactness of the phone made me never do so.