Unfortunately, Excel doesn't directly support including images or icons within dropdown lists itself. However, there are a couple of workarounds you can use to achieve a similar effect:

Workaround 1: Using a Descriptive Text List with Hidden Image Reference

1. Create your image/icon library:
- Prepare your images or icons. You can store them in a separate sheet within your workbook or use external image files.
2. Descriptive Text List:
- In a hidden sheet or a designated area, create a list of text entries corresponding to your desired dropdown options.
- Tip: For clarity, you can name these entries to reflect the image/icon they represent (e.g., "Apple Icon," "Car Icon").
3. Data Validation with List Reference:
- Select the cell(s) where you want the dropdown list.
- Go to the "Data" tab and click "Data Validation" in the "Data Tools" group.
- In the "Settings" tab, under "Allow," choose "List."
- In the "Source" box, reference the range containing your descriptive text list (e.g., Sheet2!$A$1:$A$10 if your list is on Sheet2).
4. Data Validation with Input Message (Optional):
- In the "Input Message" tab of the Data Validation window, you can add a message that appears when hovering over the cell. This message can describe the available options or even include a reference to the corresponding image location (e.g., "See Sheet1!A1 for image").

Workaround 2: Using a Combo Box with Linked Images

1. Enable Developer Tab:
- You'll need the "Developer" tab visible. Go to File > Options > Customize Ribbon and check the box for "Developer" in the "Main Tabs" section. Click OK.
2. Insert Combo Box:
- Go to the "Developer" tab and click "Insert" in the "Controls" group. Choose "Combo Box (Content Control)" from the dropdown menu. Draw the combo box on your sheet where you want it.
3. Link Combo Box to Cell Range:
- Right-click on the combo box and select "Format Control." In the "Format Object" window, go to the "Control" tab. Under "Linked Cell," enter the cell reference where you want the selected dropdown option text to be displayed.
4. Populate Combo Box List:
- Right-click on the combo box again and choose "Edit List Items." Enter your text options here (similar to method 1).
5. Link Text Options to Images:
- In separate cells (hidden or visible as needed), display your images using the `IMAGE` function or by inserting the pictures directly. Ensure the text options in the combo box list correspond to the cell references containing the images (e.g., if "Apple" is an option, link it to the cell displaying the apple image).

While these methods don't directly display images within the dropdown itself, they provide alternative ways to associate text options with relevant images for better user experience.