Play the corresponding string, and tune up or down using the appropriate peg on your instrument. Then use the Strobe view for fine-tuning.
When the desired note is to the right of the indicator, it means the pitch is too
low, and you need to tune up:
When the desired note is to the left of the indicator, it means the pitch is too
high, and you need to tune down:
Now you can fine-tune using the Strobe view, but you have
already achieved very good precision: