I am using the MMM BackgroundSlideshow module to display a new image every 10 seconds.

In custom.css I have the following codes deposited:

/*****************************************************
 * Magic Mirror                                      *
 * Custom CSS                                        *
 *                                                   *
 * By Michael Teeuw http://michaelteeuw.nl           *
 * MIT Licensed.                                     *
 *                                                   *
 * Add any custom CSS below.                         *
 * Changes to this files will be ignored by GIT. *
 *****************************************************/

.MMM-SystemStats  {
        color: #CEF6CE;
        } 
.normal,
.dimmed,
header,
.MMM-BackgroundSlideshow  {
    color: #fff;
},
.MMM-EasyPix  {
        font-weight: 400;
        } 
.MMM-SystemStats {
    font-size: 45%;
}
.MMM-darksky-hourly {
	color: #ffffff;
    }

Can someone tell me why the PI are “bigger” than when I look at them on the PC

That’s still my config

/* Magic Mirror Config Sample
 *
 * By Michael Teeuw http://michaelteeuw.nl
 * MIT Licensed.
 *
 * For more information how you can configurate this file
 * See https://github.com/MichMich/MagicMirror#configuration
 *
 */

var config = {
	address: "0.0.0.0", // Address to listen on, can be:
	                      // - "localhost", "127.0.0.1", "::1" to listen on loopback interface
	                      // - another specific IPv4/6 to listen on a specific interface
	                      // - "", "0.0.0.0", "::" to listen on any interface
	                      // Default, when address config is left out, is "localhost"
	port: 8080,
	ipWhitelist: ["127.0.0.1", "::ffff:127.0.0.1", "::1"], // Set [] to allow all IP addresses
	                                                       // or add a specific IPv4 of 192.168.1.5 :
	                                                       // ["127.0.0.1", "::ffff:127.0.0.1", "::1", "::ffff:192.168.1.5"],
	                                                       // or IPv4 range of 192.168.3.0 --> 192.168.3.15 use CIDR format :
	                                                       // ["127.0.0.1", "::ffff:127.0.0.1", "::1", "::ffff:192.168.3.0/28"],

	language: "de",
	timeFormat: 24,
	units: "metric",

	modules: [
		{
			module: "alert",
		},
		{
			module: "updatenotification",
			position: "top_bar"
		},
		{
			module: "clock",
			position: "top_left"
		},
		/*{
			module: "compliments",
			position: "lower_third"
		},*/
		
	/*{
	disabled: false,	
    module: "MMM-NewsFeedTicker",
	position: "bottom_bar",
	//classes: "day_scheduler",
	config: {
	    feeds: [
				{
			title: "20 min",
			url: "https://api.20min.ch/rss/view/67",
			encoding: "UTF-8", //ISO-8859-1
			className: "myClass",
			defaultLogo : ""
		},

    	    ]
	}
    },
		
		{
	 module: 'internet-monitor',
	 position: 'top_center',
	 config: {
		 type: 'minimal',
		 maxTime: 7000,
		 updateInterval: 120000,
		 verbose: false,
		 displayStrength: true,
		 displaySpeed: false,
		 strengthIconSize: 40,
		 maxGaugeScale: 25,
		 wifiSymbol:{
			 size: 50,
			 fullColor: '#3afc25',
			 almostColor: '#ffff0c',
			 halfColor: '#ff8c00',
			 noneColor: '#ff1111'
		 }
	 }
 },*/
	
	 {
    module: 'MMM-darksky-hourly',
    position: 'top_right',  // This can be any of the regions.
    config: {
      // See 'Configuration options' for more information.
      apiKey: 'xxx', // Dark Sky API key.
      latitude:   47.309714,
      longitude: 7.8106514,
	  
    }
  },
	
	
	
	{
		module: 'MMM-SystemStats',
		position: 'bottom_left', // This can be any of the regions.
		classes: 'small dimmed', // Add your own styling. Optional.// classes: 'small dimmed', 
		// header: 'System Stats', // Set the header text OPTIONAL
		config: {
			updateInterval: 10000, // every 10 seconds
			align: 'right', // align labels
			view: 'textAndIcon',
		},
	},
{
    module: "MMM-EasyPix",
	header: "WLAN-Code",
	position: "bottom_right",
	config: {
		picName: "guest_wifi_config.png", // Enter the picture file name.
		maxWidth: "100%",        // Size picture precisely. Retains aspect ratio.
		}
        },
		
	
	{
    module: 'MMM-BackgroundSlideshow',
    position: 'fullscreen_below',
    config: {
      imagePaths: ['modules/MMM-BackgroundSlideshow/Amerika_2018'],
      transitionImages: true,
      randomizeImageOrder: true
    }
  },


/* 
{
  //disabled:true,
  module: "MMM-AVStock",
  position: "top_right", //"bottom_bar" is better for `mode:ticker`
  config: {
    apiKey : "WPYPLO6M92PTF7PB", // https://www.alphavantage.co/
    timeFormat: "YYYY-MM-DD HH:mm:ss",
    symbols : ["aapl", "GOOGL", "005930.KS", "SCHN.SW", "UBS", "NOVN.VX",],
    alias: ["Apple", "Google", "SAMSUNG Electronics", "Schindler", "UBS", "Novartis",], //Easy name of each symbol. When you use `alias`, the number of symbols and alias should be the same. If value is null or "", symbol string will be used by default.
    tickerDuration: 60, // Ticker will be cycled once per this second.
    chartDays: 90, //For `mode:series`, how much daily data will be taken. (max. 90)
    poolInterval : 1000*15, // If your AV account is free, at least 13 sec is needed.
    mode : "table", // "table", "ticker", "series"
  }
},*/		
		
		
		
		
		/*{
			module: "newsfeed",
			position: "bottom_bar",
			config: {
				feeds: [
					{
						title: "New York Times",
						url: "http://www.nytimes.com/services/xml/rss/nyt/HomePage.xml"
					}
				],
				showSourceTitle: true,
				showPublishDate: true
			}
		},*/
	]

};

/*************** DO NOT EDIT THE LINE BELOW ***************/
if (typeof module !== "undefined") {module.exports = config;}