Hi Alex - don't you just love terminology.
Kihon for Shodokan is uke's forarm controlled by your chest with the elbow above uke's. The hand that you see grabbing the arm in your picture grabs the wrist with the other arm locking it all togeather and applying kime to uke's arm. Tori's elbow should be above uke's elbow. It affords good control with lots of options.
The explanation accompaning the animated gif
is quite interesting in its own right.