x > img')">
    <!-- NOTE: solidblue.png has an intrinsic size of 16px by 16px. -->

    <!-- Row 1: no special sizing: -->
    <div class="flexbox">
      <img src="support/solidblue.png" data-expected-width="40" data-expected-height="40">
    </div>
    <br>

    <!-- Row 2: Specified main-size, cross-size, or flex-basis: -->
    <div class="flexbox">
      <img src="support/solidblue.png" style="width: 30px" data-expected-width="40" data-expected-height="40">
    </div>
    <div class="flexbox">
      <i