Image hosting sites seem to come and go over the years leaving blank spaces in forum threads where photos used to be. This site allows direct addition of photos to the site itself, but it's important to understand that it takes up memory and bandwidth usage to post overly large photos. In fact the site imposes limits on the file size of photos posted.
Ideally the smallest possible photo file should be posted on any forum. This does not mean that the photo must appear small in a thread. It just means you should reduce the resolution of your photo. Computer screens have nowhere near the resolution of today's cameras and cell phones. So the picture you take with a twelve megapixel camera can only be displayed on a typical forum at about half a megapixel resolution. In other words, a 12 megapixel photo is 24 times as large as can be typically displayed on a computer screen.
The solution is to reduce you photo size down in your editing software to no more than 800 pixels wide then save it as a new file. To do this open your photo in your editing software and typically there will be a tool called somewhere called "Scale" or "Scale Canvas" or "Resize" or "Resize image" etc. Usually it will show the present height and width in pixels. Change the width to 800 pixels. Usually this will automatically change the height proportionately so that the image isn't reduced in one dimension only. Then save this edited image as a jpg type file using a new name so you don't overwrite your old full resolution file.
Upload this reduced filesize image to the forum and it will display nicely across the forum column size.
You can also reduce forum storage and bandwidth requirements by going smaller than 800 pixels. 600 pixels is a good width for vertical images, and smaller detail shots.
Another nice thing about reducing image sizes is when emailing or messaging family and friends personal pictures. Again, computer and cellphone screens do not need (and in fact can't use) the huge resolutions today's cameras and cellphones create. That's true of emails and messages too. A reduced file size image cuts your data usage down and is much faster to send and receive, but appears the same to the recipient. It can be frustratingly slow to receive 24 full sized hi-res images of a relative's child's birthday party, when those same pics could have been a tenth the file size, and look the same.
Hope this helps.