@Juan If you see our recommended image size instruction here https://www.themehorse.com/theme-instruction/attitude-pro/#recommendedimagesize. You will see that the recommended image size for the icon is 80px * 80px. However, if you use this image size, the height and width of the service icon is set to 40px * 40px. We have done this so it will appear more clear of retina ready devices. So, for the image size you can upload the image size of 80px*80px or 40px*40px. Now, about the border effect you could use custom css to remove this. So, in the dashboard, go to Appearance->Theme Options->Design Options Tab->Custom CSS. Paste the following css and click on ‘Save all Changes’.
.service-item .service-icon img {
border-radius: 0;
}