Image imported from derpibooru
Original Description:

Princess Luna stood in the doorway of her sister’s chambers. Not immediately see her sister the Prussian Blue alicorn called out.
“Celly. You in here?”
It was about 10 in the morning and Luna and her sister were suppose to put in a public appearance at the Canterlot Arts and Crafts Festival today.
The festival was a casual affair and as such the sisters had decided to embrace this in their choice of wardrobe for the day. Luna was wearing light tan chino shorts and a pale blue, short sleeve shirt. From direction of Celestia’s massive canopy bed the alicorn’s voice was heard.
“Back here Lulu.”
Luna found Celestia lying on her bed. The pale alicorn had been in the process of getting dressed when she’d been distracted by her longtime nemesis. The Sunday crossword in the Canterlot Courier.
Like Luna it was apparent that Celestia was planning on a casual look for today’s appearance. Although Luna knew for a fact that her sister had commissioned Rarity to make her a pair of custom denim blue jeans to wear today, and the way they hugged every curve of Celly body it was apparent that the fashionista must’ve taken many, many measurement.
Also the custom embroidered representation of Celestia’s cutie mark on the back pants pocket was kind of a giveaway.
Apparently her sister had been in the process of dressing when particularly vexing part of the puzzle had confronted her. Now the Princess of the Sun was lying her belly, topless as she glared down at the newspaper with a pencil clenched between her teeth.
“Stumped?” Luna smiled.
“Yeah.” Celestia mumbled around the pencil in her mouth. “I’ve got this one that I can’t figure out.”
“What’s the question?” Luna asked
Celestia removed the pencil from her mouth as she spoke. “A sultry or seductive presentation of an individual or individuals in printed form.”
“How many letters?”
“Five.”
“Do you have a first letter?”
“Um. The letter P.” Celestia said as she waggled the pencil at the puzzle.”
A grin slowly spread across Luna’s face as she appreciated the irony of the moment. “How about Pinup?” She asked.
Celestia perked up. “Yeah. Yeah that would work.” She glanced over at her sister. “Thanks. That one has had me stumped for the last 15 minutes. What made you think of that?”
Luna just grinned at how oblivious her sister was in this case. She crossed her arms and arched an eyebrow. “It was just a hunch.”
A moment from my anthro MLP dreamscape.