Is the Object in this Photo Mars?
Is the Object in this Photo Mars?

Almost certainly yes if it didn't move like a plane or hover and make noise like a quadcopter.
in-the-sky.org' skymap shows Mars at 117 degrees East and 25 degrees altitude at 21:43 local time in Woerden in central Netherlands yesterday. Clicking on Mars yields more information including a charts showing that it's close to opposition.
I took a photo from about 25 degrees north almost the same day I think :-) It was higher in the sky for me but just as bright and similarly cloudy. The big photo is intermediate focus. The two below it are best and bad focus. Even when defocused to 200 pixels in area it show brightly, when in focus it is saturated and so just looks like a few white pixels.