Hi Chaba,
You can insert the BB code using either the insert image button (and choosing by URL) or by toggling the BB code editor mode ( [ ] ) and using IMG in square brackets before the code and /IMG in square brackets after. You can also attach files, and then you have the choice of thumbnails (that open to a larger image when clicked) or full image.
I have switched the images you loaded to full size.
Which hosting platform are you using for the image links?
Does that help?
Pete