90 + percent of seatposts are "lay back." I haven't heard that term much, but it sounds like it was described to you that way. The non "lay back" variety are the exception, not the rule. For people with normal length femurs (relative to their lower legs) or non triathletes/time trialists (i.e., the vast majority of us), a "layback" (setback) seatpost is ideal and the norm. If you have freakishly short femurs (like me), a zero degree setback seatpost can be better. But I am the exception, not the rule.
The Thomson looks weird and slightly abnormal, as they put the setback into the tubing itself, by bending it. On most seatposts, that same amount of setback is achieved simply by attaching the saddle clamping zone further behind the centerline of the seatpost. Thomsons look a bit different in this regard, but functionally are the same. So....
Don't worry about it or give it much thought. It's a killer seatpost!