All it means is that it comes with a clock speed higher than that of the reference specs set by Nvidia. This is referred to a factory overclock. In your case 1797/1657 MHz boost/base clock vs 1733/1607 for the standard GTX 1080.
Typically higher end cards come with higher factory OCs, as well as beefier cooling solutions/board design. So they may overclock better (or just run cooler and/or quieter) than cheaper cards. The "Armor" line is MSI's budget line of cards, so no I wouldn't say it's really built to be "pushed to the max".