_sass/core/includes/contributions-band.scss

.contributions-band {
  .contrib-block {
    text-align: center;
    h4, p {
      margin: 1rem 0;
    }
    img {
      max-width: 12rem;
      @media screen and (max-width: $breakpoint-m) {
        max-width: 100%;
      }
    }
  }
}