This article will explain some detail on how sizing works for your company logo on your Campaigns, as well as the type of image that works best.
Campaign logo sizing
When uploading your company logo in your Campaign, there are no restrictions on dimensions, but the image will be resized on display with a max height of 80px, while the width can be variable. The page will try to keep the same aspect ratio of the image. An example of this is, if the original image is 800px X 1000px, it will automatically be resized to 80px X 100px.
File type recommendation
The recommended file type for the best results is a PNG file, as it's transparent background will ensure that the logo will match the background of any color selected.