According to Techtastic, the patent filed in South Korea hints at an "electronic game cartridge." No further details are given, but the design does suggest a connection to the bottom of the device that could be used to communicate with a console. This would certainly be in keeping with gaming division John Kodera's comments from May, where he noted that "Rather than separating portable gaming from consoles, it's necessary to continue thinking of [portable gaming] the one method to deliver more gaming experiences. "
It's possible, then, that the patent could be related to a future PlayStation console. Or it might not amount to anything. At Techtastic notes, Sony filed a patent in 2017 for a device that looked a lot like the Nintendo Switch, but nothing else has come of that – so not all patents go on to become products. Still, it's clear that Sony is working on something – what that something will eventually become remains to be seen.