Can I rotate pictures in stories on Houfy?

Not from inside the story editor - it has no rotate control. Rotate the picture on your own device first, then put the corrected version into the story:

1. Rotate the image in the photo app on your computer or phone and save it.

2. Go to Menu > Blog Posts and open the tab the story is in - Drafts, Published or Private.

3. Click Edit on the story.

4. Click the sideways picture in the story and delete it.

5. Click the image button in the editor toolbar (Insert Image) and upload the rotated file in its place.

6. Save the story.

Rotate is available for listing photos, which is a different tool: open the photo from your listing's Photos page, click Rotate, then Save & Replace. That does not apply to pictures inside a story.