I have had a total nightmare with pictures looking all stretched and messy on my blog. I’ve looked everywhere for a solution but no luck. Now, I think I may at last have an answer. So if there are any other bloggers having the same trouble, maybe this will help you too.
Some pictures are fine, days will pass, etc. But my last post screwed up every picture on it. Deleting and reinserting, deleting and re-uploading, even trying different Themes did nothing to help.
If you insert a picture into a post and then the post preview, or the published post, shows the pictured as a stretched greyed mess try this.
In the visual editor, click on the picture so you get these icons. Click on the ‘landscape picture’ icon on the left. This takes you to the picture editor.
In the editor is an advanced tab. Click on this and you get more options.
One of these options will be CSS CLASS, which will have some stuff in it. Delete the contents of this field.
Now save the picture. If you come back to this Advanced Settings screen, it will have put a much simpler tag in the CSS field (e.g. alignleft).
The picture should now look okay on your page.
I really hope this works for you, as the stretchy pic thing drove me nuts.
For the technical people – I think what is happening is the CSS class is trying to make the picture the full width of the post, instead of the full width of the actual picture.
If you can think of a better technical reason, let me know as I’d like to find out for sure.