Question

comment on the childish lounging of the poet Robert Frost which he expresses in the poem a roadside stand​

Answer 1

The "childish longing' the poet is referring to is the poor rural people's hopes and desires to earn some cash from the passersby.

It is in vain beacuse although they wait for the passersby to halt and buy from their roadside stand, their speeding car never stops to make any purchase. They speed off without paying any heed to the stands.