Izzy's Art Gallery
We are presented with a set of square "jigsaw pieces", each containing some fragments of art. They can be assembled into 5 framed collages:
From here, this puzzle references two different datasets, both of which are art museums associated with "Izzy", and both of which have had some notable art crime.
First, all works of art are from the collection of the Isabella Stewart Gardner Museum (ISGM) in Boston. As clued by "filling vacancies" in the flavortext, the frames surrounding them are actually the five frames left behind in the infamous 1990 art heist from the ISGM. We can identify which frame corresponds to which original stolen artwork.
Additionally, each work of art shown has been slightly modified from the original by a "fox-y art dealer." In fact, these modifications match those made by Jolly Redd, the untrustworthy fox who sells you sometimes-fake art in Animal Crossing: New Horizons (ACNH) (a video game in which you and your assistant Isabelle run an island). More specifically, each work of art has been modified the same way as one of Jolly Redd's fake paintings or statues, but the modification might have been applied multiple times.
For each given work of art, we can identify which painting or statue in ACNH has the same modification, as well as how many times it was applied here. Indexing the count into the ACNH name gives the items ART, RUFF, GLASS, BRIDGE, and HARPOON. These words have distinct lengths matching the given question marks (lengths 3-7), and the stolen paintings each contain one or two of their corresponding items, matching the associated enumeratation. Using the frames for alignment, we can take the artworks of the collage which would overlap with those items. Reading the first letters of those artists' name, as suggested by the flavortext "she likes how they're starting off," gives the answer NINTENDO.
Authors' Notes
We first conceived of this idea when trying to come up with a local Boston puzzle; we were hoping to actually send solvers to the ISGM. After a little research, that didn't seem possible, but when we found the "Isabella/Isabelle" pun with two different types of art crime (theft and forgery), we knew it was too good to pass up.
We went through a lot of different iterations with this puzzle; at various points, we were thinking of changing painting names by one letter, generating variations of paintings using AI, and making solvers find the physical locations of the stolen works in the ISGM (there's a fully virtual street-view tour). Eventually we decided on this "jigsaw" idea of using collages in the empty frames (I thought it would be a little funny that the frames become exactly edge pieces), and overlapping the original image to extract.
We tried for a while to print this as a custom jigsaw puzzle. Unfortunately, all options we found were prohibitively expensive for our budget, so we fell back on a "print-it-yourself" jigsaw instead. We hope you still had fun building it!