Navigator has a frame/event pause before updating correctly for an img element.

[seanparsons]

Describe the bug
When pasting an img element in the code editor (not necessarily the only way to reproduce this) the label in the navigator does not update correctly until something like a mouse move is performed.

To Reproduce

1. With an existing img element containing an alt attribute in the code editor.
2. Copy the existing element.
3. Paste a new copy next to the old one.
4. Do not move the mouse or press any keys.

Result: The navigator show img rather than the alt label.

Expected behaviour
The alt label should be shown without any further actions triggered.

Screenshots