Am not quite sure what the issue is and if it may be related to your browser, so I go through what I used to do. Once tou hit the "Insert Image" icon, the “From Computer” tab is automatically selected and highlighted, while the adjacent “From URL” tab has is not selected (white background). The The highlighted tab has the follwing on it...
Add an Image from your computer
Allowed Filetypes: jpg, jpeg, png, gif
[ -a blank address space- ] [Browse... ]
Upload File(s)
Hit the [Browse... ] box and then select the file you want to upload - its address will appear in the adjacent space to the left once it is selected. Then click on “Upload File(s)”, located underneath the address space. This is the 'Enter key' and that should paste the image into your post.
If for some reason that does not work, go back to the screen where you are writing your post in the “Your Message” box and scroll down to the “Additional Options” box directly underneath that. Locate the “Attachments” section and click on “Manage Attachments”. Then follow the prompts from there. This facility pastes attachments into a temporary folder when you uploading them. You then select the active attachments from that folder to paste them into your post. Once posted, these attachments become inactive and remain in this folder, so you can access them again without having to upload them again. You just need to click on the ones you want to make active.
I am assuming it hasn’t changed as I have not used it in a very long time. Hope that helps.
Also, a location for where you saw the skink will also help to ID it once you can post a pic.