[Callers] Definition, description

[Amy Wimmer via Callers]

I collected a dance recommended by someone and do not quite understand
part of it. I need a description of what the gents are doing in B2
when they "loop over their left shoulder." Can you 'splain me?

Catch a Falling Star, by Melanie Axel-Lute

A1 Nbr B&S
A2 Cir L 3/4
      Ptr sw
B1 LLF&B
     Star R (hands across)
B2 Bal star, ladies pull by to trade places while gents loop over
their left shoulder
     Star L (hands across)

Thanks!
-Amy