Two people, or perhaps two creatures, find themselves in a small pocket of peace while trouble rages elsewhere. The speaker describes "we" as "a couple of green geese," a playful, slightly odd image that suggests tenderness and a little self-mockery. Geese are companionable birds, and calling themselves geese hints at a pair who feel at ease together, maybe a bit silly or awkward, but content.
The second stanza sets up the contrast. Thunder and lightning seem to fill every other place, yet here there is only "the evening light." The word "seems" is worth noticing: the speaker isn't sure the storm is real everywhere, only that it feels that way from this quiet spot. The mood is hushed and grateful, almost enchanted, which fits the title "Charmed." It's the feeling of being sheltered, of luck, and of closeness made sharper because the world beyond looks so stormy.