Not always easy 2 do
Best images of a fetus are obtained by being able to get multiple views of the baby 'parts'/in right position/through thin layers of the abdominal wall of the expectant woman.
It is best to not get the family excited and expect that gender will be determined on an early ultrasound. If 'boy parts' are seen in the second or third trimester, then it probably is a boy. What does this photo tell y'all?