To get that error you usually have to miss a ' or a ".
since in Php you can use one inside the other with few problems you can do this.
echo 'look at all "these" double quotes that "are not escaped" because the string closes here';
or
echo "single 'quotes ' can go inside double quotes";
of course there are problems here as well. for example
echo 'he said "this won't work" but why not';
will error becasue of the word won't.
You probably have some non escaped double quotes in your link. Try changing the echo to use singles quotes for the over all wrap round. Looks like the image link is produced by someone else so thats the most likely.