img and css

In this case, Berenice, you're changing the image with the class "profile-image" to display as "block".

.profile-image {
    display: block;
}

This won't effect any other images on your page because you've specifically selected the image with the class.

Bryan, I thought that should be the case as well, which is why I got confused for the question of "Select the image and set it to be a block element" I went to the css file and I did:

.profile-photo { display: block; }

and it did not work, but when I add the block element to :

img { display: block; }

it said that was correct. So then I got confused with the idea that all my html pages are using the same css page, wouldn't doing it the img { display: block; } way, change the setting on all my photos through out all my html pages?

If you are using the same CSS page for all of your HTML pages, then yes, it would change them. However, it could be for a few reasons: 1) Your other images may be needing to be set to display: block (or already are set), in which case they would need to generalize to all images; 2) All other images are set with their own more precise selector, in which case setting a generic img { display: block; } wouldn't override each image's more-specific styles; or 3) They are just making you do it in the code challenge to check to see that you understand how to do it, and therefore may not actually matter for the actual production of all of the HTML pages being styled by the one single CSS sheet. There may be other reasons for setting this general image styling, but I can't think of any right off the top of my head.