The strength of it varies with my focus and general mental state (it is easier when I'm relaxed).
I wounder though whether somebody with aphantasia could really understand that description. After all, they would have to actually visualise a reflection to get to grips with it.
I don't take it too seriously. It's just a jumping off point for a conversation about an interesting perceptual quirk.
Unlike glasses or monitor, my "collections of attributes" when asked to actively generate a sense of things ("Picture X") seems more non-visual attributes.
Picture a chair: wood, cool to touch, weighs this much in the hand, makes a scraping noise when slid, fairly clean design with straight high back, no arms but indents for buttocks, sturdy, can be stood on to reach things. I just don't see an imaginary visual of one.
// I can mentally/visually flip through an endless card deck of them, like nielk's Google Image Search example. I don't feel like I can visually put an imaginary one in an imaginary room in my mind.
I can tell you what the colors are like, but it doesn't replace my current visual image. If I focus strongly on the sunset, I may miss things happening in reality, but reality is never fully replaced.
That said, don't take an internet social science quiz too seriously or think you're deficient. People are different.
Blake Ross noted how this seems to be related to how he just doesn't remember a lot of sensory details that other people find important. So perhaps there is some general purpose sense-memory reconstruction and recombination system. But the nature of what you get might depend on what was available. Perhaps for you, remembering a place would be about reconstructing the layout of it. For others it might be visual details, for still others important events or people they shared the space with.