Extreme large (44.5GB!) back-up files IPhone 6

Hi,

I have a 50GB space on iCloud. I did this because I constantly was getting an alert that my phone was not able to back-up because there was to little space left. Now the back-up did finish in several hours, but it was 44.5GB ⚠ big (see picture below). I think that's very strange because I have an iPhone 6 16GB. Can somebody help me out here?

Thank you in advance!

Greets,

Dénès

P.S. (Sorry about my grammar. I'm a from The Netherlands).