Not everyone in this section has D2.
An alternative method is that you could take screenshots of your items and drop all the images into an imgur album, then link the album.
This would be good in the sense that you and the person making the image don't have to be on at the same time, and the opportunity opens up to more people.
If you need help taking screenshots, there are many methods.
The old print screen, paste into paint, save, upload to imgur album.
Or take screenshots, navigate to your d2 folder, drop the images into the imgur album.
If you have Windows 10, hold the windows key and print screen (windows, alt, print screen to only capture the active tab), the image goes to your default screenshot folder.
If you don't need anything fancy and just need something simple to post pictures for your trades, paint isn't hard to learn at all.
This task would be best done with two tabs of paint open - one for your collage of cropped images, the other to paste and crop screenshots.