Brand image on Yahoo Mail app on iPhone
My colleague passed me a screenshot the other day of his iPhone Yahoo Mail app. Our email was in there, alongside Uber and Amazon's. But while Uber and Amazon had their brand logos in the preview panel (left hand side), ours had the two first letters of our company name displayed with candles. It looked like an auto-generated image (and I've certainly not knowingly put anything there).
But - the question remains, how do I control which image is shown here? I've done some Googling and can find no mention of this anywhere. Is it something I code in our email headers?
Any help appreciated!