I know, from experience, that putting full-sized pictures onto a blog brings with it a lot of problems, so I use PicSizer to shrink mine to 320 pixels x whatever ...
Here is a small photograph of my most recent painting of Jensen's Hill:
If Google is kind to me (doubtful) and my husband is correct (usual), you should be able to click on the photograph above and open another window or tab with a more detailed view of the photo, which I've stored as a Google Document.
It turns out that, using either computer screen (laptop or monitor), 1024 pixels x 768 pixels high wide works pretty well. Comments?
Instructions for doing this
First size the pictures correctly. (I use 320 pixels wide for my blog and 1024 pixels wide for the larger photo.)
Insert the smaller photo in your blog.
Upload the larger photo to Google Documents. (Upload the photo you want to come up when someone clicks on the 'thumbnail' in your blog.)
PUBLISH the photo as a Google document. Once it is published, right click onthe URL they provide, select "Copy shortcut" and move to your blog, in EDIT mode.
Left-click on the photo in your blog, then click on the icon to the right of the Text formating icon (some chain link and a green globe). When that comes up, PASTE the URL from the Google Documents (i.e. Ctl-V or Edit / Paste) into the dialog box. Select OK.
Publish your blog. Test it.
Done.