Please help translate this character from old photo of Great Grandfather.

[Pnoybro]

Hello everyone!
My family's first family reunion is coming up. We stumbled across an old photo of my Great Grandfather and all his children and grandkids. He immigrated to the Philippines and started a family there, so now nobody in our family can speak nor read Chinese. We'd love to know what the characters meant especially the big one. From the context of the photo it seems to be a celebration of some sort, maybe his birthday. I attached the two only photos from the event. 
 

Thanks so much everyone!

[TheBigZaboon]

I'm guessing, and someone will correct me if I'm wrong, but I think it is a stylized version of the character for 'Long life,shou4, and part of the word for birthday shou4chen2, although the second character does not seem to be present here.

[Kenny同志]

Zaboon is correct. The other characters in the vertical lines are good wishes, i.e. 福如東海, 壽比南山, which basically means happiness and longevity for your great grandfather.

[Pnoybro]

Thank you both very much!
We really appreciate the information!

[lingo-ling]

And it is with almost 100% certainty a birthday party.