.orbeon .xbl-fr-image-attachment .xforms-output.xforms-mediatype-image {
  width: 100%;
  box-sizing: border-box;
  display: block;
  background-color: #eee;
  border-radius: 4px;
  padding: 4px;
}
.orbeon .xbl-fr-image-attachment .xforms-output.xforms-mediatype-image img {
  margin: auto;
}