Take a look at the base product, it has a lot of information how to use it:
http://www.imvu.com/shop/product.php?pr ... id=4857278As for the bubble code the product you linked to uses:
<speech>
<bubble>
<couldBe>\n*use 80\n*use 161\n*use 164\n*use 259\n*use 288\n*use 176\n*use 2101</couldBe>
<couldBe>\n*use 80\n*use 156\n*use 230\n*use 232\n*use 260\n*use 300\n*use 2100</couldBe>
<couldBe>\n*use 80\n*use 160\n*use 175\n*use 155\n*use 287\n*use 297\n*use 262\n*use 2104</couldBe>
<couldBe>\n*use 80\n*use 290\n*use 231\n*use 163\n*use 159\n*use 253\n*use 2110</couldBe>
<couldBe>\n*use 80\n*use 252\n*use 171\n*use 175\n*use 298\n*use 162\n*use 2109</couldBe>
<couldBe>\n*use 191\n*use 215\n*use 212\n*use 220\n*use 263\n*use 2105</couldBe>
<couldBe>\n*use 191\n*use 273\n*use 185\n*use 188\n*use 183\n*use 2104</couldBe>
<couldBe>\n*use 191\n*use 271\n*use 210\n*use 180\n*use 181\n*use 2106</couldBe>
<couldBe>\n*use 191\n*use 264\n*use 186\n*use 188\n*use 184\n*use 2102</couldBe>
<couldBe>\n*use 191\n*use 268\n*use 214\n*use 211\n*use 182\n*use 2109</couldBe>
</bubble>
</speech>
What this does, it basically uses use codes to randomly put on products and use different moods. I haven't fully looked into the documention on the base product but I am assuming the <couldbe> tag means when you step onto the product, it will randomly choose one of those lines to run.
So in theory you should be able to just do this:
<speech>
<bubble>\n*use 2101</bubble>
</speech>
To make your avatar just make an angry face and put his hands on his hips without changing the clothes.
Here is a list of use codes:
viewtopic.php?f=140&t=1113