Unfortunately, when the pic's are uploaded, you have the choice of extra large, or very small. You can adjust the picture so it is a better size to see them more clearly.
In your post with the image:
-Click on "Edit MCE"
When it comes up,
-click on the image the way it is in your post
-where all the little boxes are, look for the one with the tree and click on it
-click on "appearance"
you might have to play with what numbers to put in there, but in the two boxes where it says "dimensions", put in something like 500 x 400, and then "adjust
and you should be able to see right away what the picture will look like in the post.
If it doesn't look right to you, just click again on the tree, and put in different numbers, and "adjust".