In a log entry I could not reproduce the alignment from his page: https://hackaday.io/page/1082-test, because the editor was eating some of the style attributes when the log was saved. Still, side by side can be done as a table, but it doesn't look to good:

You can further stretch the idea, and make a log entry to look like a gallery.

How you can do it

Apply the steps described in the first log entry but instead, right click on your first picture and adjust your code to look something like that:

<tbody>
    <tr>
        <td style="width:50%; text-align:center; vertical-align:middle">
            <a href="https://cdn.hackaday.io/images/your_image_number_1_here.png" target="_blank">
                <img src="https://cdn.hackaday.io/images/your_image_number_2_here.png">
            </a>
        </td>
        <td style="width: 50%; text-align:center; vertical-align:middle">
            <a href="https://cdn.hackaday.io/images/your_image_number_2_here.png" target="_blank">
                <img src="https://cdn.hackaday.io/images/your_image_number_2_here.png">
            </a>
        </td>
    </tr>
</tbody>

Note: The editor thinks he's smarter then you are, so he's applying all kinds of different unsolicited formatting, depending on what part of the project you are editing. Didn't figure out yet why the editor is sometimes mangling styles.

Or you can do it from the HaD Editor

• Write your text as usual, then insert first image.
• Click on the newly inserted image. The picture will enter in edit mode.
• Resize the picture from the lower-right white box, and make it smaller then half of the page.
• Click on the picture again, then click on the small, black "Edit" text written in the middle of the picture.
• From the 'Position' drop-down box, pick 'Left', then save.
• Insert the second picture and do the same, but align it to the right.

• Adjust the sizes of the two images
• Continue editing, then 'Publish'.

Note: In fact, it is possible all the time to do it from the HaD Editor, just that it never cross my mind to try it from the GUI. Too bad the smaller image is top aligned with the bigger image, instead of middle aligned.

:o(