Avia Chromecast and Dropbox - Does the data go through my phone? topic

Howdy...

I'm hoping this is an easy question.... I have Avia on my phone, and can happily stream to my Chromecast. Obviously this involves data going from my phone through my network to the chromecast....

My question is this: If I use dropbox on Avia (rather than local video on my phone), does the data first go from Dropbox to my phone, and then from my phone to the chromecast? Or does the data go straight from Dropbox to the Chromecast?

Inquiry minds want to know. Thanks! :)

Best,

Ben