You can still queue the upload client side and let the worker move on. Don't consider the delivery complete until the upload happens, but allow the next leg of the job to start. The client workflow can require taking the picture and clicking submit, but it can accept queueing the actual upload.

In any case, if the network is down, a spinner is a lie. It's pretending to be working on something when it's not. It should show an error at least.