The script extracts previews for all the images that are selected at the time you run the script. It extracts poster frames for any video clips that are selected at the time. You can choose a location for these files. The previews are in JPEG format, and the name contains the size of the image (for example, _MG_0233-360x240.jpg).
If you use windows explorer and click on an item like a .docx or a .jpg file you get a preview of the item you clicked on within the explorer like this. I'm trying to replicate this within my windows form application and it works fine for .docx and .xlsx files but it doesn't for image file types. To my understanding preview handlers are registered under the GUID 8895b1c6-b41f-4c1c-a562-0d564250836f in filextension/ShellEx. Using regedit you can see that .docx files have these .docx previewhandler GUID, but when you look at something like .jpg there is nothing to be found. (i.stack.imgur.com/40v6h.png). (I'm not allowed to post more than 2 links)
According to the first answer to this post (stackoverflow.com/questions/39373357/how-to-get-the-icon-path-and-index-associated-with-a-file-type) there are other locations the preview handler might be stored in for a .jpg, but they all show up empty for me. 041b061a72