The intent was to show where to place the baffle(s). It makes sense to place one mid-stream so the air to/from the fan (wherever the fan is mounted) does not bypass the condenser even though the note states:
When dimension "D" exceeds 1", it is necessary to add baffle/s above loweraccess vent, as shown, for more efficient operation in warm temperatures.
The illustration also shows how the top baffle should contour to the top grill (as mentioned previously in this post)
I also neglected to mention that option #3 is for the Innovator Refrigerator Ventilator System but shouldn't matter what vent system - the objective is to move air through the back.