These are the sizes for images that are found in the Admin Dashboard under Settings>Design.
App Logo (Upper Left Corner of Navigation Bar)
Size: 250 x 80 pixels (PNG or JPG File Format)
Size: 600 x 600 pixels (PNG or JPG File Format)
Note: This gets automatically resized to fit the page
Size: 160 x 160 pixels (PNG or JPG File Format)
Note: This is the size of the logo at the top of any communications sent from your event site through email campaigns. If you wish to have a banner image in your emails, you will need to create an image that is 600 pixels wide. Place the image at the top of the body of the email campaign or template. Make sure if you want to use a banner image in your email campaign that you delete or leave the email logo blank.
Picker Banner Logo
Size: 1200 x 400 pixels (PNG, JPG, or GIF File Format)
This is the tiny image your attendees will see on the desktop site in the browser tab.
Size: 128 x 128 pixels (PNG or JPG File Format)