You're on the right track - but you need to concatenate before the Upload File Name's variable.
This whole string ($WA_DFP_UploadStatus["WA_UploadResult1"]["clientFileName"]) results in the variable just for the file name.
In your update statement, it will look like this:
The tool automatically concatenates empty strings before and after to ensure that only the variable passes.
So to change the database data to add the file's folder in the column, you will need to concatenate like this:
"".'/images/'. $WA_DFP_UploadStatus["WA_UploadResult1"]["clientFileName"] .""
Notice a couple of things - I used single quotes to tell PHP to interpret the string as actual text. The other thing I did which you may want to change is that I added a forward slash before images to make it a root relative path rather than a page relative path. That way if you just echoed the data result somewhere later on any page of the site - regardless of folder hierarchy - the path would still be correct. If you want to keep it so the folder was still page relative, just remove that forward slash in the front.