Why not enough permissions to read the file when using a named Docker volume?

Question

Docker

I have an application running on docker-compose

version: "3.0"
services:
  static:
...
    volumes:
      - share-images:/usr/share/imgs
  bus:
...
    volumes:
      - share-images:/usr/share/imgs
volumes:
     share-images:

Bus is a java application that saves files (images) into a named volume.
static is the nginx server that renders the image data.
But by default, nginx gives me a 403 error when displaying an image. If you look at the file structure from the static container, you can see that there are not enough privileges to read the file.

# ls -al /usr/share/imgs
total 456
drwxr-xr-x 2 root root   4096 Jun 30 10:44 .
drwxr-xr-x 1 root root   4096 Jun 30 10:24 ..
-rw-r----- 1 root root 175804 Jun 30 10:44 27278103-9d2f-4599-8599-f9fc066c5bb5.jpg

If you run chmod +r on the file, then everything will work.
How should volumes be configured in the docker-compose file so that the rights are automatically set correctly in the static container?