Being older I wonder about the styles where metre/rhythm are not used. Where there is to me no beat others rave about the flow? How do these works flow without this? To me many read as prose(I guess there is such a style as 'poetic prose'? Oxymoronic to me)
In free verse, flow usually means the type of word used, to me. As in, if the atmosphere of a verse is very soft and nebulous, sticking in a harsh word totally ruins the mood and thus disrupting the flow.