diff --git a/pkg/utils/image.py b/pkg/utils/image.py
index 86230df8..f69d29d2 100644
--- a/pkg/utils/image.py
+++ b/pkg/utils/image.py
@@ -204,7 +204,9 @@ async def get_slack_image_to_base64(pic_url: str, bot_token: str):
     try:
         async with aiohttp.ClientSession() as session:
             async with session.get(pic_url, headers=headers) as resp:
-                image_data = await resp.read()
-                return base64.b64encode(image_data).decode('utf-8')
+                mime_type = resp.headers.get("Content-Type", "application/octet-stream")
+                file_bytes = await resp.read()
+                base64_str = base64.b64encode(file_bytes).decode("utf-8")
+            return f"data:{mime_type};base64,{base64_str}"
     except Exception as e:
-        raise (e)
+        raise (e)
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