single photo with music way too big when exported

Hello

I want to create a video that just shows a single frame and plays music while that frame is shown.  I want to post it on youtube.  The picture size is 72 KB.  The music is  3.92 MB.  I drag the image so that it stretches out to match the duration of the music in adobe premiere elements.  When I export the size for online sd480 is 63 megabytes.  That's more than 15 times the size of the combined disk space of the picture and the music.  Isn't the adobe premiere elements software smart enough to know that it doesn't have to multiply the size of the picture so much if it is only using one picture?  The size of the exported video should not be more than 4 MB.  Is there a way to export the file so that it produces reasonably sized output?

Sincerely,

Gamaliel Isaac