Your mandarin is definitely skinny. There are only supposed to be one line on the mandarin. If there are two and one is smack dab in the middle of its body, it’s skinny. The only one you should see is the line running through the body near the top of its body just like the line on nanocrazed’s spotted mandarin. I have a tiny mandarin less than inch and she has been here for a month. Here’s a picture of her:
You can kind of tell the top line through her body right? That’s a good line, it’s easier to tell by Nanocrazed’s mandarin