Well, thats because it is going through the process of also checking your uploads directory to see if you have any unprocessed images. If for some reason you do not process all your images allowing the upload process to be bypassed so that you can continue where you left off is considered a feature.
We used to check for an image file to force one during upload, but removed the check to allow users to continue processing images.
And while "Image uploaded successfully" may be better put as "All images in your uploads directory processed", the results are the same as it is intended.
Please do not PM me for support or sales questions. Thank you for your understanding.