I think it probably registered the sudden, way-too-close movement of its reflection - something it wouldn't have seen until it was in close proximity to the mirror. It might also have caught a glimpse of its own eyes, which reflect white because of the infrared camera.
In any case, it was certainly spooked. The funny thing is, a couple of mornings back a young deer was in the yard and caught sight of itself in the mirror. It spent some time looking at its reflection, bobbing its head up and down as if trying to figure out why the deer was visible low but not high. (And it did check behind the mirror - all of the animals who've interacted with the mirror have had a look behind it.)
My "regular" foxes were wary of it at first, but now they ignore it. Hemsworth was the least concerned of all - he had a look at it the first night it was out, but he didn't get spun up about it at all. It takes a lot to distract Hemsworth from his chow.
In any case, it was certainly spooked. The funny thing is, a couple of mornings back a young deer was in the yard and caught sight of itself in the mirror. It spent some time looking at its reflection, bobbing its head up and down as if trying to figure out why the deer was visible low but not high. (And it did check behind the mirror - all of the animals who've interacted with the mirror have had a look behind it.)
My "regular" foxes were wary of it at first, but now they ignore it. Hemsworth was the least concerned of all - he had a look at it the first night it was out, but he didn't get spun up about it at all. It takes a lot to distract Hemsworth from his chow.