I have cleaned the code to show only what matters for the example. The idea is to show spinner only while image is loading and then remove spinner and show image. Image is loaded only when element is visible on screen.

inflate.ts

import {Component, Input, Renderer, ElementRef, AfterViewInit, ViewChild} from 'angular2/core';

@Component({
  selector: '[inflate]',
  templateUrl: './inflate.html',
  styleUrls: ['./inflate.css']
})
export class Inflate implements AfterViewInit {
  @Input('inflate') url: string;
  @ViewChild('holder') holder: ElementRef;
  isLoaded = false;
  isLoading = false;

  constructor(private renderer: Renderer) {}

  ngAfterViewInit() {
    setTimeout(_=> this.inflate()); // BUGFIX: https://github.com/angular/angular/issues/6005#issuecomment-165911194
  }

  inflate() {
    let bounds = <ClientRect>this.holder.nativeElement.getBoundingClientRect();
    if(bounds.bottom > 0 && bounds.top < window.innerHeight) {
      this.isLoading = true;
      let img = new Image();
      img.src = this.url;
      img.onload = _=> {
        this.isLoaded = true;
        this.isLoading = false;
        this.renderer.setElementStyle(this.holder,
          'background-image', 'url("' + this.url + '")');
      };
    }
  }
}

inflate.html

<image-holder #holder></image-holder>
<spinner *ngIf="isLoading"></spinner>

EXCEPTION: Expression has changed after it was checked. #6005

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