AT! The "red" color under the toning is wrong. My guess is that it has been dipped in acetone or maybe something else. Crispy - NT=Naturally Toned and AT=Artificially Toned
I dunno, the pic has been brightened - most are so that's not a big deal but it would explain the underlying color. I've seen quite a few original Lincolns with similar toning so I lean towards NT. I'd wanna see the coin in hand to decide for sure.
Is that not a fingerprint or the remains thereof on the reverse? Might explain the acetone dip if indeed it did occur.
Now I know why it looks familiar. As a kid I used lemon koolaid (no sugar) to clean brass. Simply poor in water and dip. So I thought I throw a few pennies in to see how they cleaned up. Bright and shiny for a few years, then they looked like the 1909 posted. Now though.......I think I have a few left as reminders of what cleaning does.... now they look horrible. Hope this is not the case with the 1909.
Also have to consider water damage. I had some old Lincolns in BU and the dealer discounted when he bought them because the odd colors were water damage (AT in his eyes I guess).