How come tarot readings online can be so accurate?

I've recently began availing of the free tarot readings online, and most of the time the readings are quite accurate. I heard that the cards pick up on the questioner's energy, but i'm quite amazed that even if the cards aren't physically in front of you, only pics of it that can be seen via the pc screen, and it can still pick up your energy. Although when i was in the parking lot or when i was talking to my friend on the phone, it was more of like "guess if the reading is for you or for another person" since i get results that i can't relate to and it turns out it's directed to my friend. How is that possible that those cards seem to read our mind even if it's just in front of a pc?