I am having an issue where some images are not displayed in the mobile browsers on my iPhone, but I see them in all my desktop browsers. On my phone, I just see a blank box
I understand this post was from 5 years ago although,I recently came upon this problem and it was as simple as using a supported picture format for mobile browsers.
example: Instead of using a less common file type as in (.webp) try using more common types as in .jpeg or .png.