Yes, I agree with you they are different, I reckon that due to the stuttering and the direct connection between these stores, many people might use Pbtech when ordering electronics through the mall. This isn't a generalization for all electronics stores, but if it's not crucial to clarify the difference between offline and online purchases at the airport, you can simply say Pbtech if you used the mall.

what do you mean separate pickup locations? I’m pretty sure that you can pickup only from “the mall” location.

You can only buy instore at the Pbtech’s duty-free location, no pickups.