Photos I found of the 1929 International Socialist Youth Day in Vienna. Anyone have info about this? Was this a Communist movement?

by Illustr84u

I was given a box of photos that I've wanted to share with the world but don't know how. Included are photos of my grandmother & her brother's involvement in organizing their local SAJ group (Socialistche Arbeiter Jugend or Socialist Workers’ Youth) to go to the 1929 International Socialist Youth Day in Vienna. I can find very little on the internet about this event nor do I know much about the SAJ so any info would be appreciated.

Here's a photo of their group leaving for Vienna. https://imgur.com/Iw78dhz

The next photo was sent to my grandfather months earlier in the USA about their efforts. I believe it is written in code but I'm not a native German speaker. (back inscription) https://imgur.com/stv1cVH

"The Easter folk has already arrived at our home/ dormitory / holiday home / youth's home. Because some of us had put their eggs too close to the steam heater our room population has grown. And now, what to do? Whereto with this fidgetiness? No one [female plural in German] wants to surrender their bed into a warm and soft biddy nest. We will be forced now to install a chickenfarm on the roof and attic. We are still waiting for the permission. Happy Easter 1929 Os." Os is my Uncle Oskar.

(photo front) https://imgur.com/DCHCUPt

Full album: https://imgur.com/a/Kicl2

Illustr84u

I found this reference but I have no idea how to access. https://www.net-film.ru/en/film-65404/