Hmm, couldn't reproduce this on any of my devices. The images appear side by side and I can even scroll left / right in the article.
What version of Webview is your device running? You can find out by going to Developer options -> Webview Implementation. Both my devices have Chrome Stable which seems to render the HTML from the article as intended.
In fact, I see no problem with the article layout itself. I see the 2 pics properly and I can also scroll the text left and right.
The 'problem' is that when I press one of the 2 pictures, it pops out like an image viewer overlay but it is way too big. The top action bar stays displayed and although I can still scroll left and right the expanded picture, it is then more than twice as large as my screen.
As far as my system Webview version, I couldn't find anything in this regards under the developers options. I must say that my OS is quite outdated though as I'm still running on MM (CM13) hence the potential issue...
Anyhow, it's really a minor issue and I just flagged because I didn't think that is was a matter of webview and thought it was just a layout issue (android:layout_height=fill_parent instead of a wrap_content kindda thing...).
Here's what I get in portrait mode