Mike has direct access to the graphic system that's used for the stream. We can make this conclusion with one video where the graphics are messed up and are displaying only the first two cards scanned as if it were a NLH hand, instead of all 4 cards for the PLO hand they are actually playing (
video here).
Assuming the scanners at the table still scan all 4 cards placed over the reader and that the graphics are only wrong because they are just displaying whichever first two cards were scanned (due to the graphics settings for the stream), then we can safely conclude that Mike has someone on the inside (likely on within the crew that handles the streaming, graphics, etc.) sending him or otherwise allowing him direct access to these graphics in real time. I suspect it is in real time, as you can see Mike in the video frantically trying to have his cards scanned, something I haven't seem him do in any other hand.
If he had some sort of device on him that could hijack the table's scanners and display what cards they are seeing on his phone, he would have likely played this hand like his normal cheating self (like a god, confident, not panicking the whole hand). BUT since he didn't, we can assume he does not have any sort of way to hijack the tables scanners.
If anyone can confirm that the dealer at the table doesn't change how many cards it is supped to scan and the the table scanners don't have different game modes, then we now know FOR A FACT that Mike has someone on the inside. This would also explain why Postle's performance suffers whenever Justin Kuraitis is out of town. If he was able to hijack the scanners directly, he wouldn't need an inside man every time, just for the initial setup.