There are a few ways you can manipulate this. Here is one way, using the daspect command you used before:
[X,Y,Z] = peaks(20);
figure;
tiledlayout(1,2);
nexttile; imagesc(Z); daspect([1 1 1]);
nexttile; surf(X,Y,Z); daspect([1 1 2.5])
You could also use axis square:
[X,Y,Z] = peaks(20);
figure;
tiledlayout(1,2);
nexttile; imagesc(Z); daspect([1 1 1]);
nexttile; surf(X,Y,Z); axis square
