Signature pic

Noticed it was gone..a website upgrade no doubt. I have some pics on Imgur I can use...but I don't get the size part of it right. Even though I specify a thumbnail size, the link I use to Imgur does not CHANGE size on the forum. I've tried a couple of different types (don't even know what they are...[media], [website] ) and such.

There is no reason to have a large pic as part of a signature, seems to me.

Pointers please, on how to resolve the issue?

Thanks.