Ok, I will give more details.
About image:
Indexed, 16 colours, 64x128, 11.6KB.
Regarding screenshot:
Firstly, the one on the left is the view in NSE, and its also how it shows up in the game. The one on the right is the PNG image I imported in.
The only difference is on the edges on the sprites's right side. Comparing 2, You can see that the sprite on the left has really jagged lines on the headband, left hand sleeve, the tail like structure located under the sprite's left hand, the bottom and top part of the pants. Resulting in really blocky lines. While the PNG image has smoother lines.
All I did was import the image, and thats how it turns out.
Detail enough?