load(isLazy, reload) {
    if (this.slide && this.usePlaceholder()) {
      if (!this.placeholder) {
        const placeholderSrc = this.instance.applyFilters('placeholderSrc', // use  image-based placeholder only for the first slide,
        // as rendering (even small stretched thumbnail) is an expensive operation
        this.data.msrc && this.slide.isFirstSlide ? this.data.msrc : false, this);
        this.placeholder = new Placeholder(placeholderSrc, this.slide.container);
      } else {
        const placeholderEl = this.placeholder.element; // Add placeholder to DOM if it was already created

        if (placeholderEl && !placeholderEl.parentElement) {
          this.slide.container.prepend(placeholderEl);
        }
      }
    }

    if (this.element && !reload) {
      return;
    }

    if (this.instance.dispatch('contentLoad', {
      content: this,
      isLazy
    }).defaultPrevented) {
      return;
    }

    if (this.isImageContent()) {
      this.element = createElement('pswp__img', 'img'); // Start loading only after width is defined, as sizes might depend on it.
      // Due to Safari feature, we must define sizes before srcset.

      if (this.displayedImageWidth) {
        this.loadImage(isLazy);
      }
    } else {
      this.element = createElement('pswp__content', 'div');
      this.element.innerHTML = this.data.html || '';
    }

    if (reload && this.slide) {
      this.slide.updateContentSize(true);
    }
  }
Preload content

@param {boolean} isLazy
@param {boolean} [reload]