You can choose one of four Twitter Card formats for how your tweets will display to your followers, based on your letter's content. Select your format by going to Username > Your Profile > Preferred Twitter Card. Your chosen format will be used for any archive links you tweet automatically or manually.
1. Summary Card
The Summary Card includes the first 200 characters in the letter as a summary and a thumbnail image if one is available. For a thumbnail to be displayed, an image has to be included in the letter, at a minimum size of 120px x 120px.
2. Summary with Large Image Card
The Summary with Large Image Card will also include the first 200 characters of your letter as a summary, and it requires an image to be included at a minimum of 280px x 150px. If an image is not included in the letter, then the Summary Card format will be used as the default.
3. Photo Card
The Photo Card excludes the letter's summary and displays a large image instead. This format requires an image to be included at a minimum of 280px x 150px. If an image is not included in the letter, then the Summary Card format will be used as the default.
4. Gallery Card
The Gallery Card displays four images along with a summary in the Twitter Card. This format requires that four images are included in the letter at a minimum of 280px x 150px each. If a letter only has 2 or 3 valid images, then it will default to the Summary with Large Image card first, and the Summary Card format if the images don’t fit the dimensions.