Cigar-shaped UFO over Lander, Wyoming on July 2017

On July 20, 2017, a cigar-shaped UFO was spotted over Lander, Wyoming, USA. A witness caught a picture. What is it?

Witness report:

I noticed a very interesting looking cloud bank. i was standing on a sidewalk in front of my girlfriends house. I had my iphone 6s plus so i decided to take some photos. I took several photos zoomed in and several normal photos. I took these photos in rapid succession. I put my phone away and went inside. I did not see this object or notice it at the time. I was looking through my photos several weeks later and only then realized there was a cigar shaped UFO in the very last picture of the series. Having photos that were taken one second apart and it appears in only one photo is interesting to say the least. The very best part is when i was taking photos of this cloud bank I was thinking how it looked like a UFO disguised as a cloud. To me it appears as if this craft is docking with a mothership of sorts. I have shown several people and was not sure where to share this until now. Thank you for any interest in this, i would greatly appreciate any feedback or comments.

Source, 05th March 2018