Well, it seems that there are themes on WordPress that are similar to the templates on Blogger. I am using the Interiors theme which includes the repeat of your first photo as a “Featured Photo.” It is centered and larger than the original photo. That is why it appeared that photos had been imported twice. You can remove the original, and the featured photo stays put in this theme. If you change themes, and choose one that does not have the “featured photo” option, you lose that original photo.
Hmmn, so what to do? I created a folder called, “Blog photos” in “My Pictures.” I am right clicking on the featured photo in each post in this theme, and saving a copy to “Blog photos.” I have only edited a couple of pages, so it shouldn’t take long to save copies of the deleted originals.
Now, I need to decide if I’m going to continue using the Interiors theme, or choose another. You can create a preview if you “install” the theme on your dashboard. Each theme has different options for customizing. One thing I’d like to change about Interiors is the font size and the post title color (pale gray on beige.) I can’t. I do like that I can change the header image and the background color. I can also add an image as a background. That’s too busy for the bold, simple, focused design I’m wanting, now. Who knows what I’ll want tomorrow? I’m just going to look at it and think for a day or two.