nginx overrides default files to /usr/share/nginx/html/ after starting nginx server. dockerize nodejs app with nginx

Below is my docker

FROM gitlab/gitlab-ce as VCS
WORKDIR /opt/
RUN git config --global http.sslVerify false
RUN git clone --branch master  --single-branch https://examples.git

FROM ruby:2.3.0
RUN gem install compass
RUN gem install sass

FROM node:8 as BUILD
COPY --from=VCS /opt/starreviewers/UI/ /opt/starreviewers/UI/
WORKDIR /opt/starreviewers/UI/
RUN npm cache clean --force 
RUN npm install
RUN npm audit fix --force
RUN npm install -g grunt-cli
RUN npm install bower
RUN npm install karma grunt-karma
RUN grunt --no-color clean --force
RUN grunt --no-color build --force

FROM nginx:1.13.3-alpine
RUN rm -rf /usr/share/nginx/html/*
COPY --from=BUILD /opt/starreviewers/UI/dist/ /usr/share/nginx/html/
RUN ls -lrt /usr/share/nginx/html/ 
CMD ["nginx", "-g", "daemon off;"]

whenever I build this docker image with below command

docker build  --tag=starrevassociate:gs 

It built the app and copy all files from opt/starreviewers/UI/dist/ folder to /usr/share/nginx/html/
correctly, even it prints all files with ls -lrt command .

But whenever I run that image file with command

docker run --name starrevassociate -p 80:80 -d Nginx

the container is up and running with nginx default index.html page.
why is it removing all files that I have copied from built opt/starreviewers/UI/dist/ folder to /usr/share/nginx/html/

in /usr/share/nginx/html/ folder only deafult files are there

Source: StackOverflow