Treat it like a combination of text types. It is a multimedia medium.
Discuss:
Placement--> Where things are on the page, sizing, divisions, where your eye is drawn, bar lines, vector lines. Where is the navigation bar etc.
Language---> Written techinques, you should be suitably familiar with these by now. Expect more bullet points, lists, sub headings (almost a report style layout), in text links and so forth. Formal or informal.
Visual---> Again, the images and the techniques involved here. They should RELATE TO THE SUBJECT MATTER IN THE TEXT. Could even be links themselves. Colours on the page, any repeating motifs, patterns, symbols, graphs, charts, tables, FONTS, highlights, Backgrounds, text boxes.
Audience/Purpose--> Is this continuous? Ease of exploration. Tidy. Logical arrangment?
Extras---> Sounds, animations, shout out boxes, feedback buttons etc. It could get too complex with many of these.
I would not suggest doing a web page, but if you're a techie you may as well, it could give you a leg up as it is unlikely to be used by many.
Useful if you are doing a "How successfully is blah represented by blah in your texts" sort of question.
Edit: LINKS ARE IMPORTANT. Hyperlinks and so forth show the TEXT TYPE, if you do not recognise these you will be at a disadvantage. It's like doing a newspaper article and not recognising that there is a specific style.