that looks like the "return flange" type tray, which has the edges rolled back in against the sides to give a nice smooth edge.
Hi Adam and welcome,
Good comment, I'd forgotten that cable tray comes in two types.
At the very least, I would have used some plastic cable clips (the type with the nail in them) to tidy the wires up as they were run into the equipment.
If there's one thing I can't stand the sight of, it's messy cable runs.
Cable ties seem to be the way to go these days, wether the actual cables themselves are held to anything or not.
