What is the refinance appraiser looking for?

I live in a fixer-upper. A few years ago I removed an old brick fireplace that was in really bad shape. This left a hole in the wall. On the exterior, this hole is covered with plywood only. Fast forward a few years; I am getting a refinance on my house and the appraiser came out. The appraiser’s report contains several items that need to be addressed before the refinance can go through. One of the items is the lack of siding in that area.

To be completely honest, more work needs to be done on that part of the house than just installing siding, and I am trying to contact and hire contractors to get that work done. But I am wondering whether what the appraiser is looking for is just for that raw plywood to be covered over with siding. In other words, if I go over to Home Depot and buy several packages of siding and install them over the weekend, is that going to be enough? The report is no more specific than “problems that need to be mitigated: siding” with a photo of the area in question.