Values of T206 portrait vs. other poses

[Throttlesteer]

This may have been covered in the past. But, what is the driving factor for portrait poses fetching higher $ than the other poses? If you look at the pop reports (and believe them), in most cases the portraits are no less rare (with the exception of some higher grades). In some cases, they're much more plentiful in low-->mid grades.

Is the common thought that they're more attractive or desirable? I may be one of the outliers, but I tend to prefer the more "action" oriented poses (Cobb bat off, Lajoie throwing, Matty dark cap, Young bare hand, etc...). I was just curious what others thought.