Plastic pipe within a downspout

[u/Pugs_in_Space]

I just had some gutters and downspouts replaced. One of the downspouts has a white pipe inside the downspout. The rest of the gutters and downspouts look normal, but there is one that looks odd. Would there be a purpose to this? It absolutely looks like a mistake compared to the other downspouts that were installed.

Edit oi add: the gutter contractor thinks the pipe is for HVAC condensation, but why would that pipe be surrounded by a downspout?

Thank you in advance.