There are two options for how images are displayed on catalog tiles: Cover and Fit.
In the Cover view, images fill the entire tile, with semi-transparent banners overlaying the image with the Item name (and optional donor name/item number) as well as the Bid banner.
The Fit view displays the full image between the Name and Bid banners. In both views, Users can click on the tile to view complete details.
Fit View (w/o optional donor/item#)
To Select Settings:
Go to Site Settings > Items > Catalog > Catalog Settings: