I was also thinking of doing that too. What do you mean for copyright reasons? Am I not allowed to take a photo of a specific deck and use it for example as my cover photo? Even if it's not as a logo?
Copyright can be tricky - Ace is correct to mention it - to put it simply, if you use a photograph of a deck for a news or say blog article, it can be classed as editorial and most times this is ok. However if you use an image commercially, to promote a business or for a logo, you need to have copyright to the deck in the image (or permission from the artist / copyright holder of the deck or artwork). It can also depend on how the photo is taken - eg. If the tarot cards are on a table with lots of other things and not the primary piece of the image - but if it is just a photo of the cards themselves it is a different story.
There are exceptions to this, where if the copyright has expired - which sometimes occurs after a period of time, or the death of the artist etc - this can vary depending on the image. This is perhaps why Ace mentioned the RWS.
To avoid issues in this area you can check out micro stock sites like IStock photo, Shutterstock, Fotolia etc - as they have stock images of tarot that can be licensed to use (often at a very small fee) - and they have already addressed the copyright issue, or have a property release from the artist of the deck from the photographer. I have been doing stock photography for a number of years - and have found some of my more popular images are of my tarot deck, as I can take the photos for commercial use as I also own the copyright to the deck.
Cheers CF