Did you see it in a side by side comparison with any other bird species? It's easy to make that mistake when you see a picture of the bird by itself. I made that mistake, thinking senegals were fairly big, but they're not really that much bigger than sun conures. Bit longer, but not by much. Green Cheek Conures are also rather small, as well. The size difference between Green Cheek and Sun Conure were surprising to me at first.

I saw it singly in pictures. Then I saw a WCP at my bird store next to a BHC and sun conures. Tiny little guys. I was expecting like a smaller african grey since pies are related to amazons, so I thought they'd be a little bigger. I also saw a BCC next to a TAG and blue crowns are really big conures.