A drink from an imaginary cup
zach bender said:
time to think would be more four swords.
Nice point there. And I think you're right. 4/Cups isn't about "Thinking" so much as dreaming and feeling.
Remember that cups of water are used for scrying. Also as mirrors where people see their dream reflection. This person has three cups, but they're letting their emotions get caught up in a fantasy fourth cup.
As YDM42 put it, this is not necessarily bad. Some people need to shut their doors, or go off alone to rest under the sky, and just let their emotions float on a fantasy. It's a form of relaxation, of letting creativity and feeling replentish themselves by drinking from that imaginary cup.
In some cases, people often talk about how imagining making love to someone else actually can improve their love life with their current partner.
The negative of the card is if it's indicating stagnation and boredom or even homesickness (which sound like a nice interpetation for it). In that instance, the person is coming to feel that the grass is greener elsewhere, and they might take action that they'll regret.
But the card need not be negative. Letting the emotions drift and flow with one's imagination can be very theraputic and restorative.