@HumanGhosts  
Here’s a bit of headcanon to fix that, since Twilight has extensive experience with time travel magic, but doesn’t know everything about the subject, taking into account she hasn’t yet read that new book they mentioned early in the episode, she doesn’t know that in Equestria’s “original” time line, there never was a program in place to recognize ponies who are prompt to return books on time, that’s a small anomaly that appeared after Twilight traveled through time too much.  
The Canterlot Library never had a strict policy about being prompt about returning books or any penalties for being late or even failing to bring the books back at all, as the library is so closely tied to Princess Celestia, they enjoy great financial support from her to keep the shelves stocked with brand new books at all times.  
Because Twilight Sparkle has jumped across time and parallel dimensions on multiple occasions bits of her psyche have imprinted on history and created anomalies in odd little places.

@orbsah  
Well, yeah, that’s what would have made it an awesome detail. It would have shown they either based The Point of No Return on a random detail from Amending Fences, or that they intentionally put it there in Amending Fences because they thought they might base an episode around it later.

@Ping_chan  
Yeah. XD

Those two books have been sitting in the same spots on that circle thing in the middle since season 5?

@HumanGhosts  
They don’t know it back then.

Wouldn’t that have been an awesome detail though if they’d had the picture there already in S05?

Note. Ther is no Twilight photo in the first pic.