Why are images and signatures sometimes store with a complete url and other times are store with a partial google drive path?

To be clear I am talking about the value that is stored in the spreadsheet (or airtable table). I have seen the three below. Note that I edited the urls so they do not link to files. The first form causes a lot of issues, and breaks in certain scenarios when working with airtable. The other two work, but I can not understand how to have signatures saved in either of those formats. Images use format 3, in our apps, but signatures have used both 1 and 3…and I have no idea why. I would like to force it to 3.

Job_Images/461c7f44.Dropoff Signature.014419.png