They look the same to me. Thickness of hair could be natural variation or environmental difference in soil and light of the growing conditions. Hard to say.

And are those really Espostoas? They don't look right to me. (Pseudo)Espostoa melanastele is a valid species, but those look more like Oreocereus.

Oreocereus usually have larger thicker needles sticking through the fluff.

And Espostoas have crinkly, rough wooly surfaces with small spines, not at all like the wooly mammoths pictures above.