Image size when listing items using shortcodes

I am trying to create a page to credit and list the authors of the items on my site. They have had their photographs taken, and I would like to display them along with names and brief bios. Ideally I would eventually like to provide a link, under each author’s name, to the items they have created.

I tried to do this using PHP at first, but found that this can no longer be done, so I am trying to use shortcode for the first time. My authors are stored as items of the type “Person”, with their names under Title, bios under Description, and photos attached as files. When I make a Simple Page called “About”, and use a shortcode like:

[items item_type="person"]

it displays gigantic images of the authors dwarfing their little descriptions to the right.

How can I fix this?