The only PNL that cannot be faked is one that shows PNL along with quotes and an account number approximating real-time. Typically this would involve taking a phone pic of your front-end and uploading it immediately to a thread or a video host (YT, vimeo, etc). The quotes (or news) would match the time stamp of the post within seconds/minutes.
I've used that exact process due to the numbers involved. I don't think it's necessary for sstheo to go to those lengths due to the numbers he's dealing with here.
Actually, I think any type of redacted screenshot of the front-end (if you meant the broker trade execution platform) that's posted within 1 - 2 minutes obviously is not enough time for someone to fake something in comparison to the same screenshot being uploaded several hours later or the next day.
Regardless, I'm not a fan of broker statements (clean white background with black fonts). Too easy to fake.
wrbtrader