"From the outside?"
I’m afraid not. For one thing you’d need an article: von der Außenseite. More importantly however, Außenseite quite literally means the outer side of something in German. For example if we’re talking about a window, its Außenseite would be the outer glass pane. It is not used to refer to the general area “outside” – that would be außen or draußen (or as a preposition “outside the window”: außerhalb).
Btw, a small clarification in case my original correction to PhilipMars9 generated confusion: I did not mean that you can’t combine the adverb außen with a preposition like von; in fact you can. What I was trying to say was that an adverb like außen cannot take an article because only nouns take those.