I would not say that the cards absorb energy by being open during a working. That being said, you can “contaminate” your insight after you have done a working if you have not done something (like a grounding meditation) that can bleeding out into a reading with how you interpret the cards. For example, let’s say you just did a love spell and immediately do a reading for in regards to a job. You still have that focus of love in the back of your mind that can make a reading confusing when you try to switch gears towards the job.
I actually treat divination as it’s own ritual and will give myself a few hours after a different ceremony to help clear my mind.