This is right from the E-Commerce Site Transformation WishListItem:
<img src="<%# GetSKUImageUrl(100) %>" alt="<%# EvalText("SKUName", true) %>" />
Here is the full transformation:
<%@ Register Src="~/CMSModules/Ecommerce/Controls/ProductOptions/ShoppingCartItemSelector.ascx" TagName="CartItemSelector" TagPrefix="uc1" %>
<div class="wlItem whblBox">
<div class="left">
<a href="<%# EcommerceFunctions.GetProductUrl(Eval("SKUGUID"), EvalText("SKUName", true)) %>" title="See detail of <%# EvalText("SKUName", true) %>">
<img src="<%# GetSKUImageUrl(100) %>" alt="<%# EvalText("SKUName", true) %>" />
</a>
</div>
<div class="right">
<h2>
<a href="<%# EcommerceFunctions.GetProductUrl(Eval("SKUGUID"), EvalText("SKUName", true)) %>" title="See detail of <%# EvalText("SKUName", true) %>" >
<%# EvalText("SKUName", true) %>
</a>
</h2>
<p>
<%# LimitLength(Eval("SKUDescription"), 500, "...", true) %>
</p>
<span class="price">Price: <strong><%# GetSKUFormattedPrice() %></strong></span>
<div class="actions">
<uc1:CartItemSelector id="cartItemSelector" runat="server" SKUID='<%# EvalInteger("SKUID") %>' SKUEnabled='<%# EvalBool("SKUEnabled") %>'
ShowProductOptions="false" />
<%# EcommerceFunctions.GetRemoveFromWishListLink(EvalInteger("SKUID")) %>
</div>
</div>
<div class="clear"></div>
</div