Media Assets window: Imported tab: does not load thumbnails

### Prerequisites

- [x] I am running the latest version of ComfyUI
- [ ] I have custom nodes enabled

### What happened?

As seen in screenshot:

It does not load the thumbnail. But when I click icon on upper left and "Download", i can download the file just fine.

### Steps to Reproduce

As seen in screenshot:

It does not load the thumbnail. But when I click icon on upper left and "Download", i can download the file just fine.

### How is this affecting you?

Visual/UI issue only

### ComfyUI Frontend Version

v1.43.18

### Browser

Chrome/Chromium

### Console Errors

```javascript

```

### Logs

```shell

```

### Additional Context

_No response_

┆Issue is synchronized with this [Notion page](https://www.notion.so/Issue-12326-Media-Assets-window-Imported-tab-does-not-load-thumbnails-3656d73d3650811cadbceeb52edc84a6) by [Unito](https://www.unito.io)