Why keep images in tiles graphic array?

By this time, there are duplicated tiles, one as an image and one as graphic:
``` javascript
const initialTileCount = tiles.length;
for (let i = 0; i < initialTileCount; i++) {
let tempTiles = [];
for (let j = 0; j < 4; j++) {
tempTiles.push(tiles[i].rotate(j));
}
tempTiles = removeDuplicatedTiles(tempTiles);
tiles = tiles.concat(tempTiles);
}
console.log(tiles.length);
```
Example:

Start by tracing where the tiles array is initialized and how rotate() and removeDuplicatedTiles() are used in the shown expansion loop. Compare the image and graphic entries in the linked screenshot, then determine whether both representations are required. Done means the issue has a documented rationale or an agreed, tested simplification.

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