Before I close this up, is this legit location for light at bottom of stairs? Yes, switch at top and bottom, and light at top as well. Through some quirk of symmetry, this can light (of 12 total), ended up HERE, and lines up with the other cans in a row (not pictured. And yes, that is an emergency light, not required per local code but I be losing power in ice storms. I see a lot about how many candle feet, etc...the stairway has to be illuminated, but nothing about how many inches/feet the light source has to be positioned in relation to the top and bottom. The top one is almost directly over the top step. Bottom one, it does the job. I'd hate to add another can there, it will look odd, but I got final coming up soon else have to pull a new permit under 2017, and I'll take an odd-placed can versus re-permitting as a new build.
The only thing that worries me is odd placements of the lights and switches requires more wires than a typical /3 cable includes, and that invites bad wiring, e.g. using two 12/2 cables where you need a 12/4 cable.
Also, in this day and age, remember the light switches need real neutral at the switch. 2-wire switch loops (3-wire if 3-way) are outlawed in 2011 NEC.
Don't know about code. But the top light seems to cast a shadow. The actual step is in partial shadow from the step above it. I would like to see another picture with the stair light on, all other lights off, and it dark outside.
If it was my stair I would try to put a light in the ceiling above the 2-4th step from the bottom. This is unpleasant ladder work install. I presently have one on above the 7th form the bottom, and in an otherwise dark house, it can make for misperceptions where the edge of the step is.
Another way to light the stair would be those rope lights. Run a strand along each side on the stringers just behind the treads. You could also incorporate rope lights into the currently non-existent railing.