I was using pokersnowie preflop advisor to understand squeezing ranges from blinds. I observed 2 patterns

1. When the cold caller is not SB, software advises to use a polar range is suggested

Below is the squeeze range from BB when CO opens and BTN cold calls

2. When the cold caller is SB , a linear range is suggested
Squeeze range from BB when BTN opens and SB flat calls

Question:
can anyone explain why there is difference in strategies between the the 2 situations, i.e. Polar vs Linear