>>713082683>They're supposed to be able to do thatYes, but not necessarily held in that position for hours at a time.
>and they can be crisscrossed in the top or bottom picture depending on the angle you view the arm fromActually untrue.
If you were to view the top picture from above/below, the bones would be visually overlapping, but they'd still be spatially parallel with each other in the sense that the segments which connect to the elbow have an orientation identical to the segments which connect to the wrist.
If you were to view the bottom picture from above/below, the bones would still be crossing each other, both visually and spatially. More specifically, the orientation of the segments which connect to the elbow would be offset 90 degrees from the orientation of the segments which connect to the wrist.