For the sake of completeness, here's why this test is failing:
The regular UploadWizard checks for duplicate images on the target wiki and prevents users from uploading if it finds a duplicate image. (This btw is why the regular UploadWizard test uses the ChunkyPNG utility to create near-unique images for each run of the UploadWizard test.)
But the Mobile upload page will allow users to believe that they have uploaded a duplicate image. When the Mobile upload page presents the image thumbnail of the duplicate image on the success page, the alt text containing the image description is correct, but the actual href link itself is empty. Refresh the uploads page and the duplicate image thumb is no longer visible.
So this test as written would pass once and only once on a static target wiki like beta labs.