The store owner is warned that s/he is "[acting in a way that causes] Jewish children in the neighborhood to stumble."
Please click to enlarge:
The note writer appears to be upset because the clothing is not 'Jewish,' the haircuts are not 'Jewish,' and the poses are not 'Jewish.'
A rough translation of the note:
What are you trying to portray [?] Shall the House of Israel be like the goyyim [gentile nations], God forbid?
Where is the Yiddish chain [grace]?
Shame on you for [acting in a way that causes] Jewish children in our neighborhood to stumble.