Uploading Images and Timer Icon or Uploading progress bar

Question

Having a hard time trying to connect the upload progress bar to the actual upload. My developers say that all timers/progress bars are just psychological and that they aren't actually working. I don't understand or believe that since all of the sites that have image uploads seem to have a progress bar that coressponds perfectly with the upload.

 

Can you please direct me on this? I just want to have the uploaded images have a timer that tells the user how long the upload will be or at least what percentage of the upload is completed. If the upload is not actually working, I want the site to tell the user that it's not working (when an upload pauses, so do the working parts- the timer on my site just spins and has a random percentage that stops at 94% for the longest time.)

 

Thank you for your input!