Overflow panel tag in dashboard

[ext_fiserm]

Hello,

i want to make one panel of the same size and present there pictures of any size. Pictures which fit there are okay but pictures that are bigger are hiding inside of the pannel. I tried to use CSS overflow to present the picture in the front and put other panels to the background. But its not working. Everything what is posted into the panel stays in the panel.

Can you help me please?

This is a part of my code:

    #panel {
        z-index: -50;
        overflow: visible;
        max-height: 200px;
    }

Best regards,
Michal