Looking at the color key, I can see that "BK" stands for black. The instruction at the bottom of the key clearly states: "Draw a black circle in F4 and H4."
This confirms that I need to draw black circles in positions F4 and H4 on the coordinate grid. Looking back at the penguin image, I can see that position H4 (the right eye) already has a black circle, but position F4 (the left eye) is still just a white square.
Therefore, to solve this problem, I need to add a black circle to position F4 to complete the penguin's face according to the instructions.
The solution is to draw a black circle in position F4 on the coordinate grid. This will complete the penguin's eyes as instructed, with black circles in both F4 and H4 positions.
Since the puzzle appears to be already completed in the image (with H4 having a black circle), the task was likely to verify or complete the drawing by adding the black circle to F4 if it wasn't there. In this case, adding the black circle to F4 would complete the mystery picture according to the given instructions.
Parent Tip: Review the logic above to help your child master the concept of printable coordinate graphing hidden pictures.