The new 3DPhoto demo refers to uploading and downloading but it works without a network connection

https://storage.googleapis.com/tfjs-models/demos/3dphoto/index.html

is very cool but I don’t understand why it has buttons labelled upload and download when I disconnected from the network and it still worked fine (except for the download button). A real strength of TFJS is that it can run completely on the user’s browser so why all this talk of uploading and downloading?