In reply to nufkin:
> That's what I was expecting after some Wikipedia reading, but it doesn't look anything like that - seems to be just a string of letters LGgrpsEbmLeisgHYidj/TJvM /inspalcxkyivnSvbnYK/ and so on. Maybe I'll try some of the suggested editors to see if they can make more sense, but since I can't have made it in the first place I can probably live without it if I can't work it out.
That's not actually 'gibberish' - open a jpg file with a text editor to see what real 'gibberish' looks like.
The little snippet you've posted (assuming it's copied and pasted) looks base64 encoded - which you can find free online decoders for (e.g.
https://codebeautify.org/base64-decode/ ) if you want to figure out what it says. You should still have curly braces and quotation marks inside the file if it is json-compliant.