Icons are not showing after creating virtual Host on Xampp for laravel

Hi, I have installed Platform 4.0 by Cartalyst. it was working okay on localhost/dev/public but would like to access it via app.dev

I created a virtual host by in these steps

I opened the httpd-vhosts.conf file located at F:\xamp\apache\conf\extra\https-vhosts.conf

and replaced everything with this

# Virtual Hosts
#
# Required modules: mod_log_config

# If you want to maintain multiple domains/hostnames on your
# machine you can setup VirtualHost containers for them. Most configurations
# use only name-based virtual hosts so the server doesn't need to worry about
# IP addresses. This is indicated by the asterisks in the directives below.
#
# Please see the documentation at 
# <URL:http://httpd.apache.org/docs/2.4/vhosts/>
# for further details before you try to setup virtual hosts.
#
# You may use the command line option '-S' to verify your virtual host
# configuration.

#
# Use name-based virtual hosting.
#

#NameVirtualHost *:80

#
# VirtualHost example:
# Almost any Apache directive may go into a VirtualHost container.
# The first VirtualHost section is used for all requests that do not
# match a ##ServerName or ##ServerAlias in any <VirtualHost> block.
#

<VirtualHost localhost>
    DocumentRoot "F:/xampp/htdocs"
    ServerName localhost
    ServerAdmin admin@localhost

    <Directory "F:/xampp/htdocs">
        Options Indexes FollowSymLinks
        AllowOverride FileInfo
        Order allow,deny
        Allow from all
    </Directory>

</VirtualHost>

# Development
<VirtualHost app.dev>

    DocumentRoot "F:/xampp/htdocs/dev/public"
    ServerName app.app
    ServerAdmin admin@localhost
    ServerAlias app.dev   

    <Directory "F:/xampp/htdocs/dev/public">
        AllowOverride All
        Order Allow,Deny
        Allow from all
        Require all granted
    </Directory>

</VirtualHost>

Then I opened my hosts file located at C:\Windows\System32\drivers\etc and added this line to it

127.0.0.1       localhost        app.dev

so my hosts file looks like this

127.0.0.1       localhost          app.dev
127.0.0.1       127.0.0.1

and now I am able to open my app.dev but the images do not resolve.

I updated the URL path in the app.php

'url' => 'http://app.dev',

How can I fix the images issue?