Both pictures look PERFECTLY natural!
One looks like a perfect transition to the other.
I know its easy for me to say, but you're worrying unnecessarily.
If anything, these pictures would remove any doubt about your hair being other than natural.
Much weirder if you had the same style/cut/density etc year in and year out!

The fact is, last time anyone saw your head, you'd shaved it, or had a hat on.
Now you have let it grow back. Of course people will comment on that, but thats normal.
If no one mentions it, that would be REALLY odd and would tell you something was too wrong for them to mention.

I had a friend who had always had short straight hair cut in to a flat top.
I didn't see him for a year and when I did, he had this mop of ringlet curls!
I had no idea his hair was curly. I couldn't stop looking at it!
After half an hour I was used to it and can't imagine him any other way now.
However, if I thought he was suddenly wearing a wig, I wouldn't have said a thing.
You look great in both pictures.
Be confident.