OMR, you have been in FL long-enough to know Winn Dixie (I'm not sure if you're a native). The remark about store gondolas reminded me of my early work history.
Back in the 1970's, Winn Dixie was what Publix is today, in FL. The #1 grocery chain. They had something like nearly 80% of the market. Over time, the % of market attributable to them declined, and that of Publix rose. Now, Publix is the Big Kid on the Block.
I moved to So. FL in the early 1970's and I got a job in a week, working on a construction co. building and re-modeling Winn Dixies. It was where I got my construction education. I had never worked in construction before, I was in my early 20's, and this proved to be a good way to build my knowledge. I worked with a 'colorful' group of co-workers, most of whom were journeymen in their respective trades. Some were masters. I paid attention, and I learned about nearly everything on a commercial job: layout, excavation, foundation, concrete formwork, framing, masonry, electrical work, carpentry, tying steel rebar for columns and tiebeams, and setting it in-place, pouring concrete in forms and for slabs, and much-more.
One of my favorite things to do was the layout of the movable shelving when the store was preparing to open. A couple of trailers would get dropped-off in the parking lot, and once the store closed for the evening, we would start removing the old gondolas and replacing them with the new gondolas. I was renting an apartment w/acquaintances, so no shop, nor anything to put in one. I had no call to take some gondolas of my own from the old ones we removed.
We would work all night, from 9 p.m. to 7 a.m. We got the next day off, and it was usually a 2-day job to remove/replace the gondolas. I eventually found a need for a couple of gondolas and shelving, and they moved with me several times.
Your guess about the purpose of that bent wire sounds reasonable. The translucent plastic piece hanging from the hook may be for those 'sale' tags: BOGO, New; Now more per package; $ saving ticket; etc.