diff --git a/folium/features.py b/folium/features.py
index dc9349ef01..1c18f426db 100644
--- a/folium/features.py
+++ b/folium/features.py
@@ -1862,14 +1862,14 @@ class CustomIcon(Icon):
 
     Parameters
     ----------
-    icon_image :  string, file or array-like object
-        The data you want to use as an icon.
-        * If string, it will be written directly in the output file.
-        * If file, it's content will be converted as embedded in the
-        output file.
-        * If array-like, it will be converted to PNG base64 string
-        and embedded in the output.
-
+    icon_image : string or array-like object
+        The data to use as an icon.
+
+        * If string is a path to an image file, its content will be converted and
+          embedded.
+        * If string is a URL, it will be linked.
+        * Otherwise a string will be assumed to be JSON and embedded.
+        * If array-like, it will be converted to PNG base64 string and embedded.
     icon_size : tuple of 2 int, optional
         Size of the icon image in pixels.
     icon_anchor : tuple of 2 int, optional
diff --git a/folium/raster_layers.py b/folium/raster_layers.py
index 0ff6ef9948..5e846e9bd2 100644
--- a/folium/raster_layers.py
+++ b/folium/raster_layers.py
@@ -243,14 +243,17 @@ class ImageOverlay(Layer):
 
     Parameters
     ----------
-    image: string, file or array-like object
-        The data you want to draw on the map.
-        * If string, it will be written directly in the output file.
-        * If file, it's content will be converted as embedded in the output file.
-        * If array-like, it will be converted to PNG base64 string and embedded in the output.
+    image: string or array-like object
+        The data to overlay as an image.
+
+        * If string is a path to an image file, its content will be converted and
+          embedded.
+        * If string is a URL, it will be linked.
+        * Otherwise a string will be assumed to be JSON and embedded.
+        * If array-like, it will be converted to PNG base64 string and embedded.
     bounds: list/tuple of list/tuple of float
         Image bounds on the map in the form
-         [[lat_min, lon_min], [lat_max, lon_max]]
+        [[lat_min, lon_min], [lat_max, lon_max]]
     opacity: float, default Leaflet's default (1.0)
     alt: string, default Leaflet's default ('')
     origin: ['upper' | 'lower'], optional, default 'upper'
diff --git a/folium/utilities.py b/folium/utilities.py
index 9210bf59e6..09fd20c5de 100644
--- a/folium/utilities.py
+++ b/folium/utilities.py
@@ -169,12 +169,14 @@ def image_to_url(
 
     Parameters
     ----------
-    image: string, file or array-like object
-        * If string, it will be written directly in the output file.
-        * If file, it's content will be converted as embedded in the
-          output file.
-        * If array-like, it will be converted to PNG base64 string and
-          embedded in the output.
+    image: string or array-like object
+        *  If string is a path to an image file, its content will be converted and
+           embedded in the output URL.
+        *  If string is a URL, it will be linked in the output URL.
+        *  Otherwise a string will be assumed to be JSON and embedded in the
+           output URL.
+        *  If array-like, it will be converted to PNG base64 string and embedded in the
+           output URL.
     origin: ['upper' | 'lower'], optional, default 'upper'
         Place the [0, 0] index of the array in the upper left or
         lower left corner of the axes.