Hello Paula,
Good question. There are a couple of content options for the blog pages. If you go with the excerpt option, it will show a short snippet of your post’s text. It will also show the featured image if the post is set to use the image format and a video if it’s a video format post.
WordPress filters everything out of the excerpt except text, so images, text formatting, forms and other items will be left out.
If you need to show images that are inside your post’s content, you’ll want to use the content option. You can cut off your post’s content on the blog page by inserting a more tag into your post’s content. That will let WordPress know where to cut off the content.
If you have any questions, let me know.
Take care,
Bill