Posting pictures is not hard you can upload to a site like imgur, and then post the link here.
You think you send the units to the "escrow"? Escrow DOES NOT test equipment. The buyer does.
Devils Advocate, I have seen escrow done both ways, not often though. The standard is generally the seller would show proof of a functioning miner, then upon arrival the buyer would test the unit, upon verifying it's functional the escrow releases the funds.
This is where using a trusted forum escrow is beneficial as they can ensure it is done properly.
[WTS] Guidelines I suggest OP and anyone transacting on the forum read this, it shows what to look for, and provide as far as information goes. If conditions in this post are not met I do not trade nor do I advise anyone else to trade. This goes for all forum sales.