mschleisner ...the gallery you submitted your photo to is called 'Wallpapers'.
One specific criteria for a wallpaper is for it to be in the proportions of a recognised desktop wallpaper....aka screen resolution.
These days, with widescreen monitors [LCD] there are considerably more acceptable resloutions, eg 1680x1050 is now a valid format...but it was not always.
Currently still the most commonly used is 1024x768.
Either way, proportions of a 'portrait' format photograph will not be accepted as wallpapers as they are never going to suit a desktop proportion.
Site members have the opportunity to upload ANY image of ANY size to their Photo Gallery, as that is NOT intended for suitable wall images but for such things as a standard photograph such as you continually attempt to submit to 'wallpapers'.
I'll post a link to mine...as an example of the ideal location.....[though site is being recalcitrant at the moment]....