Looks like a Docker configuration issue with the exposed volume:
InternalServerError: EACCES: permission denied, mkdir '/var/lib/ghost/content/images/size/w1600'
at new GhostError (/var/lib/ghost/versions/3.35.4/node_modules/@tryghost/errors/lib/errors.js:10:26)
at _private.prepareError (/var/lib/ghost/versions/3.35.4/core/server/web/shared/middlewares/error-handler.js:53:19)
at Layer.handle_error (/var/lib/ghost/versions/3.35.4/node_modules/express/lib/router/layer.js:71:5)
at trim_prefix (/var/lib/ghost/versions/3.35.4/node_modules/express/lib/router/index.js:315:13)
at /var/lib/ghost/versions/3.35.4/node_modules/express/lib/router/index.js:284:7
at Function.process_params (/var/lib/ghost/versions/3.35.4/node_modules/express/lib/router/index.js:335:12)
at next (/var/lib/ghost/versions/3.35.4/node_modules/express/lib/router/index.js:275:10)
at handle404 (/var/lib/ghost/versions/3.35.4/core/frontend/apps/private-blogging/lib/middleware.js:166:20)
at Layer.handle_error (/var/lib/ghost/versions/3.35.4/node_modules/express/lib/router/layer.js:71:5)
at trim_prefix (/var/lib/ghost/versions/3.35.4/node_modules/express/lib/router/index.js:315:13)
at /var/lib/ghost/versions/3.35.4/node_modules/express/lib/router/index.js:284:7
at Function.process_params (/var/lib/ghost/versions/3.35.4/node_modules/express/lib/router/index.js:335:12)
at next (/var/lib/ghost/versions/3.35.4/node_modules/express/lib/router/index.js:275:10)
at Layer.handle_error (/var/lib/ghost/versions/3.35.4/node_modules/express/lib/router/layer.js:67:12)
at trim_prefix (/var/lib/ghost/versions/3.35.4/node_modules/express/lib/router/index.js:315:13)
at /var/lib/ghost/versions/3.35.4/node_modules/express/lib/router/index.js:284:7
Error: EACCES: permission denied, mkdir '/var/lib/ghost/content/images/size/w1600'