I don't believe this was asked yet and you didn't seem to mention this but when you are trying to upload the picture and when you are on the site are you using a phone, tablet, or a computer?
Some phones and tablets naturally have a issue with uploading pictures in a different format than what it was originally.
If you are using a computer, as someone else has mentioned, try control+r to refresh it and see if that works. Macs are command+r I think.
Also, what browser are you using? That can help us help you further.
I don't think it's a glitch on the site itself but it's a possibility.
Since you have said it is in a jpg. format it shouldn't be much of a issue to fix.
Have a blessed day! :)