https://github.com/pnp/list-formatting/tree/master/view-samples/icon-link-tiles をリメイクしたフォーマット

remake-icon-link-tiles.json

{
  "$schema": "https://developer.microsoft.com/json-schemas/sp/v2/tile-formatting.schema.json",
  "hideSelection": true,
  "width": 200,
  "height": 170,
  "formatter": {
    "elmType": "div",
    "children": [
      {
        "elmType": "a",
        "style": {
          "text-decoration": "none"
        },
        "attributes": {
          "href": "[$URL]",
          "target": "=if([$NewTab] == true, '_blank', '')"
        },
        "children": [
          {
            "elmType": "div",
            "attributes": {
              "class": "ms-bgColor-themeLighterAlt ms-bgColor-themePrimary--hover ms-fontColor-themePrimary ms-fontColor-white--hover"
            },
            "style": {
              "display": "flex",
              "flex-wrap": "wrap",
              "width": "180px",
              "height": "150px",
              "margin-right": "10px",
              "margin-top": "10px",
              "box-shadow": "2px 2px 4px darkgrey"
            },
            "children": [
              {
                "elmType": "div",
                "style": {
                  "text-align": "center",
                  "margin": "auto"
                },
                "children": [
                  {
                    "elmType": "div",
                    "attributes": {
                      "class": "sp-row-title"
                    },
                    "txtContent": "[$Title]"
                  },
                  {
                    "elmType": "div",
                    "attributes": {
                      "iconName": "[$Icon]",
                      "class": "ms-fontSize-su"
                    }
                  }
                ]
              }
            ]
          }
        ]
      }
    ]
  }
}