SIDEBAR MENU LABEL issues

Hi.
I’d like to e helped in how to edit images added in a sidebar menu with navigation label.
I did like that as suggested in your forum:
<img src="myimage.jpg">
Couple of question
1) how can I have the smaller image (the seahorse) centered horizontally?
2) when I inspect the side bar images element added in this way, I notice that they have not alt and title description, should I add them manually?

Thanks in advance
Daniel

yes sorry because i changed now
look here

but I replaced the image with a bigger one so now you cant see if centered or not.
In case the images would be smaller, how to center them?

Also
I put

/* 3 COLUMNS styling */
div .av_one_third {
    margin-left: 1%;
    width: 32.66%;
}

but it does change also section with 2/3 not only 1/3, why?

thanks

Now i added this code line

div .av_two_third {
margin-left: 5%;
    width: 66%;

and it worked

So what gonna happen now if I’d add a page with 4 columns?

Cheers