The header section has two main areas for dynamic content, the background image and foreground copy. The copy will always appear over the background image from the bottom and will extend upwards the more copy there is. The height is dependent on the background image and has a minimum height of 300px and a maximum of 550px. Specs below should help determine the most optimal sizing but if the copy height exceeds the height of the image, then you may see some unwanted results.

Section View Icon Section View
Small: 512 × 600+
Medium: 1024 × 250+
Large: 2048 × 340+
Character Limit: 100
Character Limit: 400