Oh, I read 200mb.
My apologies you wrote picture symbol. Pictures are Rasters.
What is the symbol representing? I think you would be better off not using a picture symbol.
There are thousands of symbols available via the ESRI Font set.
If you have to us that particular Vector Symbol you should get a Font Creator and create a font from your symbol. True Type. However, the drawback to this would be that the font would need to be installed on every computer that uses that GIS