How to style the square in Image overlay

Hi, I would love to use image overlay, especially now it is in V2, and so much more powerful. however, i cannot find how to style the actual square.

Image 1 shows the style i want (square at the top with rounded edges), and image overlay square underneath

Ive tried to use the same Custom class to get the rounded edges but Image 2

shows the result, where the straight square edges are showing over the rounded corners, is there a class in image overlay that i can alter to give me rounded edges? @Norm

It would be good if this could be made so text or an icon can be put on top of the image too, I have the bric and can modify it to do things but would be so good to have it so I can have for example name of a profile or item and then it does its thing when you hover over.

Agreed, I have to create the picture with writing in affinity photo, export that. The put into blocs