How to see the full description of a YouTube video with the iPhone?

I don't see how to expand the video description with the iPhone.Am I not seeing something or is it a bug?

Added (1). It is the YouTube app also by the way sorry.

Use Negative Space Effectivel
It's easy to think of the FedEx logo as a great example of how positioning fonts can bring out hidden meaning in the space between the letters. You can see the arrow
between the 'E' and 'X' in FedEx and all that this conveys about progress, direction and movement without using anything more than a font. While experimenting,
remember to check whether it still works at all sizes. If your company sells wrenches, for example, you might choose a blocky font that makes the space between the
c and h look like part of a wrench. This may be too obscure to be noticeable when you logo is viewed on a small screen or in newspaper print.

Are you using the YouTube App or the mobile site with Safari?

Hmm it works fine for me with the app? Maybe a bug. Try deleting it and downloading it again, or see if there's an update for the app.