The dog holds 戌, seven to nine in the evening — dark now, the hour of keeping watch. The position explains the character: guarding. It sees the risk first, because its job is staying alert while everyone else relaxes.
You'll recognise it here: the sense that something isn't right arrives early in you and is usually justified; your standard for loyalty is high, and being let down once is remembered for a long time; and you'll go disproportionately far for people you care about without feeling it needs thanking.
Running well, the dog is what makes people genuinely settled: what you said you'd do gets done, and in a world of talking, that alone is rare. Blocked, it goes two ways. One is worry becoming control — so much risk visible that you want every variable managed. The other is loyalty given to the wrong object and held there for years, because leaving feels like betrayal. The dog's practical lesson is checking whether they're worth it first. Your loyalty is a real resource and deserves to be deployed like one.