It does look like a smeared out seagull or cloud.
But the pick was taken because the object was seen. It's not that it was visible on the photograph afterward, while not seen in real. Also the article says multiple witnesses, which is interesting. Maybe it was drone?
A second UFO was spotted in the same region of Dorking as the previous article I found. :
http://www.dorkingandleatherheadadvertiser.co.uk/Second-mysterious-object-seen-Dorking-skies/story-22963353-detail/story.html