It helps to make sure that your clients/customers (whatever you want to call them) know how to save files properly.
This does not work:
because all it does is save that small thumbnail image that happens to to be:
at a puny 178 x 178 pixels.
You might want to make sure that they click the image they want and save the actual file using the download button on the bottom right part of the screen/window:
Because nowadays, due to the proliferation of certain things (rant to come later… I promise), you just cannot trust that the image you delivered will be used the way your client had intended… and it might not be their fault.