What does it mean when you get a torot reading and the cards are face down?

In tarot reading the cards can be layed on the table face down. That does not necessarily mean anything else, than that the card have not yet been opened, and the reading has not yet started.

It really depends on the Table the reader is using, if there is a meaning for the cards being face down. Usually one could put it this way: 'the message stays hidden'.

But if you meant what does it mean if the cards are upside down aka face up but the picture 'wrong way' from the reader's point of view, then usually the meaning of the card is opposite to the meaning the card normally says.

This is not actually this straight-forward, in reality there are a vast list of alternative meanings for a card, if it´s upside down.