Problem pulling Tweets with media using Dukt's Twitter API plugin
The return from craft.twitter.get() is not an array of tweets, but a response object, where the actual tweets are nested in an attribute called data.

Not tested, but from looking at the plugin docs, something like this should do it:

{% set response = craft.twitter.get('statuses/user_timeline', { tweet_mode:'extended' }) %}

{% if response.success %}
    {% for tweet in response.data %}
        ...
    {% endfor %}
{% endif %}