On the weak side of the formation (bottom of the image), the corner is playing man coverage if #1 attacks vertically (>8 yards). If #1 breaks in or out prior to 8 yards, the corner will sink to his deep quarter of the field and prepare for any deep out-breaking routes from #2. The weak-side safety plays with standard Cover-4 rules where he plays man coverage on #2 vertical or doubles #1 if #2 breaks short.
On the strong side of the field (top of the image), the defense is playing with standard Cover-2 zone rules. The safety is responsible for a deep half of the field and the corner is playing his flat responsibility. A corner at this depth is referred to as a "cloud" corner and is often used to high/low bracket a threatening receiver (e.g. Calvin Johnson, above). This corner is taught to funnel the receiver to the inside at the snap to minimize the void between himself at the half-field safety. He will then turn his eyes to the quarterback and jump any short/flat routes.
The strong-side linebacker plays his hook/curl zone while the weak-side linebacker and slot defender play hook/curl and flat zones, respectively.
Cover-6 is an easily disguised coverage as it can be veiled as a number of coverages prior to the snap. The 2013 Baltimore Ravens were particularly fond of this playcall and periodically played Cover-4 on one side and 2-Man on the opposite.
Outside References
3) Football's One-Gap 3-4 Defense
4) Understanding coverages and attacking them with the pass game
5) cover 6
6) Loaded Zone
