What does "see the elephants" mean here?
Tyrion climbed to the castle library and tried to distract himself with Beldecar’s History of the Rhoynish Wars, but he could hardly see the elephants for imagining Shae’s smile.

Hi. I have looked up the idiom in the dictionary, but I still don't understand what it means in this context. Please help with my understanding.
Thank you.

Question

What does "see the elephants" mean here?
Tyrion climbed to the castle library and tried to distract himself with Beldecar’s History of the Rhoynish Wars, but he could hardly see the elephants for imagining Shae’s smile.

Hi. I have looked up the idiom in the dictionary, but I still don't understand what it means in this context. Please help with my understanding. 
Thank you.

Answer

It's not an idiom; in one of the Rhoynish wars, 100 war elephants were used. This would have been an impressive sight, but Tyrion's imagination was distracted.

Answer

It means to see something incredibly obvious, like a large elephant. In context, the passage is saying that Tyrion was trying to read but imagining Shae’s smile distracted him so much that he wouldn't have noticed anything, even an elephant. It's more idiomatic than literal.