It should be possible to rotate upright images in Coyo.
If you want to upload pictures to Coyo that were taken in portrait format it is the case that these pictures are not uploaded vertically to Coyo, but are inserted crosswise into the post and you have no chance to rotate them. So you have to rotate the image on your PC, re-shape it and upload it again. Surely you could make this easier by offering the picture directly on Coyo with an option to rotate it. That way you can save yourself the tedious intermediate step and post the article directly.