I just noticed this deformity on my 2016 13" MBP. I've had the computer since November but just noticed this today (maybe it's been there for longer and I just didn't see it). It's slightly raised and the regular pattern of it makes me think that it's due to something inside the case pushing outward. I'm really careful with it, so I don't think I could've caused it somehow. Anyone have any idea what's happening?