Domino Designer, Notes Client and Domino server should support the AVIF image format.
It is a much superior to JPEG and PNG and is a modern image format.
It is royalty free and has multiple advantages such as quality and size, and especially quality related to the file size.
All major browsers support it today.
A little info here: https://netflixtechblog.com/avif-for-next-generation-image-coding-b1d75675fe4