I don't see where else to put this but, when I tried to post my design the first 2 times it posted someone else's picture, so I changed my file's name and tried a third time and it worked that time. It appears that if your file has the same name as one of the files already uploaded the site just uses the one thats already uploaded instead of yours.
p.s. Devs if you are reading this can you please delete #773 and #774 cause they were my failed attempts at uploading my file. (the name is Christian Eshelman and the one that is mine is the one with the black background.)