You're really overestimating what happens in actual jury trials. When I served on a jury, a lawyer presented photographs of evidence as evidence. Like, I'm talking paper printouts of photos that were taken on a cell phone. Juries aren't full of engineers, as a general rule. If the average person on Reddit will see a screen shot of a text message and assume the conversation happened, why wouldn't an average juror? The only burden of proof is if a lawyer can convince the jury a conversation happened.