I believe what the author is saying that in these sculptures you can see the taste, at the time, for having uniform or homogenous statues, in the sense that the outline is essentially a straight line, the sculpture is one big, solid, unified mass.
This would be in contrast to later greek sculptures, such as the discobolus, which has limbs that extend outward, breaking the idea of a straight line. (you can see the difference easily if you google "Geneleos group" and compare the two).

meaning with no movement, no breaking up, just one whole mass