Nvidia is binning SKU's of the same chip - the higher binned chips can be sold by the AIB's with a pre-applied OC and are sold at a higher cost to the AIB and ultimately to the consumer. The lower binned chips (lower cost to AIB and ultimately consumer) can not have any pre-applied (factory applied) OC settings. It does not necessarily mean the user can not apply an OC, just that the AIB (Add In Board Partner) can not apply an OC setting. Its Nvidia's way of segmenting the cards. The Non OC cards/Chips are sold closer to original MSRP - the higher binned cards can be sold with a factory applied OC and at a higher cost. You can save a little money on a card and apply your own overclock ( your mileage will vary as with all over clocking as to what you will actually obtain) - or spend a little more upfront and get a card with a factory OC and settings applied already ensuring your OC (as stated on specs). Here's a link to a video specifically discussing the RTX 2070 SKU's but applies to the other SKU's as well. https://www.youtube.com/watch?v=6EAbHsa8eCU

TLDR
one has a factory applied Overclock (higher boost clock) than the other.

-90YV0C62-M0NM00 = no factory OC applied - User can still OC , meaning you can use ASUS tweak or MSI Afterburner etc to apply an over clock.
Base/Boost clocks 1515/1740

-90YV0C60-M0NM00 = factory OC applied, meaning the card comes by default with higher base and boost settings. The user may still be able to apply a better OC but at minimum you should get the higher factory applied base/boost clocks out of the box.
Base/Boost clocks 1515/1890

Check the base/boost clocks listed in the specs for each card with the matching reference numbers - you will see the differences. Again this is not an Asus only thing - It is Nvidia and the requirements they set on the AIBs regarding the different chip SKU's